17772 questions

### Make u the subject of the formula D = ut + kt²

When answering a question like this it is important to understand the key words in the question and what it is asking you to do. The Key word in this question is 'Subject'. The subject of the formula (D = ut + kt²) is D. The question is asking you to rearrange the formula to make u the subject ( isolate it onto one side of the = sign ).There are a few principals to remember when doing this: Change side, Change Operation ( if you move a term from one side of the = to the other you change the operation to do the opposite therefore if it is a + you change it to a - ). Also, what you do to one side of the = you must do to the other. The solution: D = ut + kt² Step 1. -kt² from both sides = ( D - kt² = ut ) Step 2. ÷ t from both sides = ( (D - kt²) / t = u ) Answer: u = (D - kt²) / t
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Answered by Shannon, Maths tutor with MyTutor

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### How do you form the present subjunctive in French?

How to form…1.     take present tense indicative, 3rd person plural (ils/elles)Donner – to giveIls donnent Remplir – to fillIls remplissent Vendre – to sellIls vendent Je donneJe remplisseJe vendeTu donnes Tu remplisses Tu vendesIl/elle donne Il/elle remplisseIl/elle vende Nous donnions Nous remplissionsNous vendions Vous donniezVous replissiezVous vendiezIls/elles donnent Ils/elles remplissentIls/elles vendent  *irregulars include :FaireJe fasse… continue patternPouvoirJe puisse… continue patternSavoirJe sache… continue patternAllerJ’aille… continue patternVouloirJe veuille… continue patternAvoirJ’aie, tu aies, il/elle aie, nous ayons, vous ayez, ils aientEtreJe sois, tu sois, il/elle soit, nous soyons, vous soyez, ils soient
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Answered by Anna, French tutor with MyTutor

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### What is the difference between ser and estar?

Whilst both verbs mean "to be", ser is for permanent qualities/states, whereas estar is used for temporary qualities and locations. For example "el chico es perezoso" (the boy is lazy), this suggests the boy is always lazy as a permanent quality, however using estar (el chico esta perezoso) would suggest the laziness is only a temporary quality of the boy. Estar is also used when stating the location of something, for example Anna está en Nottingham. QUESTION TIME: choose the correct phrase... El perro que esta negro esta en el parqueEl perro que es negro esta en el parque El perro que esta negro está en el parque El perro que es negro está en el parque
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Answered by Anna, Spanish tutor with MyTutor

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### When do you use the subjunctive?

The subjunctive is a mood rather than a tense - it expresses an idea in a specific manner. A subjunctive phrase suggests ideas of wish, hope, fear, uncertainty or other attitudes/feelings toward a fact or an idea. Often, 2 different people are involved: the first one wanting/hoping/ fearing that the other person/subject does something. There are 4 tenses of the subjunctive mood: present, past, imperfect and the pluperfect, however only the present and past subjunctive are used on a daily basis (pluperfect and imperfect are used in rare literary cases). There are many "trigger phrases" for the subjunctive that will need to be learnt, such as "pour que" - with these phrases, you are expected to know that the following verb will need to be conjugated in the appropriate subjunctive tense.
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Answered by Anna, French tutor with MyTutor

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### How do we regulate body temperature homeostasis?

Homeostasis is the maintenance of a constant internal body environment. One of the most important factors that needs be kept constant is the body temperature. Body temperature needs to be kept around 37 degrees Celsius so that enzymes in the body can work best. To regulate this we have a thermoregulatory centre. This consists of the hypothalamus in the brain which receives information from receptors in the blood and the skin, detecting internal and external temperature.
When the body is too cold, nerve impulses are sent to erector pili muscles causing hairs on skin to stand up. This traps an insulating layer of air around the body. Sweating stops. Skeletal muscles also contract rapidly, causing shivering. The contractions need energy from respiration and some of this energy produced by respiration is released as heat. The blood vessels also constrict reducing the blood flow to the capillaries. Less blood flow means less heat is lost .This is called vasoconstriction. When the body is too hot, Hairs on skin lie flat. Sweat glands release more sweat. The evaporation of water cools the body down as the heat energy is transferred from the body to the environment. The capillaries also undergo vasodilation. Vasodilation is when the arterioles widen allowing more blood to flow into the capillaries and so there is more heat loss.
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Answered by Alice, Biology tutor with MyTutor

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### Solve the simultaneous equations:

My first step is to assign the two equations number 1 and number 2.3x + y =-4 (Number 1)3x-4y=6 (Number 2)There are numerous methods to solve these simultaneous equations (knowing which one to use when will be discussed in the sessions).It is important to note, that any of the aforementioned methods can be useful in this question. However, in an exam situation, choosing the correct method is important to save time.In this case, you can see that both equation number 1 and equation number 2 have a common term, 3x. This means in this case the subtraction method is the easiest one to use. I will therefore subtract number 2 from number 1.To do this, it is important you keep the terms organised and the signs in the correct order. (3x-3x) + (y-(-4y)) = -4-6Remembering that two negatives equate to a positive, the above equation can be re-written as:(3x-3x) + (y+4y)) = -4-65 x y = -10To find y from the above equation, you will have to divide by 5. However, whatever you do to one side of an equation you must do to another! (This will be a rule that will be taught as part of a previous important concepts lesson).Therefore,(5y)/5 = -10/5y = -2Once you have the value of one of the terms you can put it into either of the two equations (number 1 or number 2) to find the 'x' value.In this problem, equation number 1 is easier to solve. This is because the 'y' factor is not being multiplied by any factor.Therefore, 3x+(-2) = -43x-2 = -43x =- 2x = -2/3Checking your answer:To finally check that i have the correct answer i will take the two values of x & y (x=-2/3 & y=-2) and place them in equation number 2 to see if it gives me the correct answer.3x-4y = 6 (Number 2)(3 x -2/3) - (4 x -2) =-2+8 = 6As y was calculated from number 1, It has been shown that x=-2/3 & y=-2 both satisfy equation number 1 and number 2. Therefore, they are correct.
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Answered by Dhruv, Maths tutor with MyTutor

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### Solve 5x - 2 < 3x + 11

5x - 2 < 3x + 11 --> 5x < 3x + 13 (Add 2) --> 2x < 13 (Subtract 3x) --> x < 13/2 (Divide by 2)
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Answered by Feyisola, who has applied to tutor Maths with MyTutor

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### 10x + a = 8x + c, make x the subject

Begin by collecting like terms on each side (so all the terms involving x on one side, and all the other terms on the other side). Take 8x from both sides: 10x + a - 8x = 8x + c - 8x 2x + a = c Take a from both sides: 2x + a - a = c - a 2x = c - a Divide both sides by 2 (as x must be alone):(2x)/2 = (c - a)/2 x = (c - a)/2 This is our answer
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Answered by Feyisola, who has applied to tutor Maths with MyTutor

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