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y = (x + 2)(x + 5)

steps as follows:x times x = x²2 times 5 = 102 times x = 2xx times 5 = 5xthen add these together:y = x²+ 7x +10x = -2, -5; y = 0, 10

Answered by Georgie L. • Maths tutor

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Use the addition formulas: sin(x+y)=sin(x)cos(y)+sin(y)cos(x), cos(x+y)=cos(x)cos(y)-sin(x)sin(y) to derive sin(2x), cos(2x), sin(x)+sin(y).

sin(2x)=sin(x+x) =sin(x)cos(x)+cos(x)sin(x) =2*sin(x)*cos(x); cos(2x)=cos(x+x) =cos(x)cos(x)-sin(x)sin(x) =[cos(x)]²-[sin(x)]² Now let x+y=a and x-y=b, then x=(a+b)/2 and y=(a-b)/2. ...

Answered by Ioana S. • Maths tutor

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Why do you need simultaneous equations?

This is an example of a simultaneous equation - 2X + Y = 5X + 3Y = 10 You can think of X and Y as apples and oranges from a market. You know that if you buy 2 apples and 1 orange it cost £5, but this does...

Answered by Amelia G. • Maths tutor

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Raya buys a van for £8500 plus VAT at 20%.Raya pays a deposit for the van. She then pays the rest of the cost in 12 equal payments of £531.25 each month. Find the ratio (in simplest form) of the deposit Raya pays to the total of the 12 equal payments.

Raya buys a van for £8,500 x 1.2 = £10,200. Total of 12 equal payments = 12 x £531.25 = £6375. Raya's deposit = £10,200 - £6375 = £3825. Ratio of the dep...

Answered by Andrew B. • Maths tutor

27486 Views

A ladder of length 4.5m is leaning against a wall. The foot of the ladder is 2.3m from the base of the wall. What is the angle the ladder makes with the wall?

This is an application of trigonometry. The right angle in this case is between the wall and the floor and the hypotenuse is the ladder. The angle between the wall and the ladder can using the sine of the...

Answered by Nicci F. • Maths tutor

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