MYTUTOR SUBJECT ANSWERS

580 views

Solve the simultaneous equations '2X+Y=7' and '3X-Y=8'

In order to solve this question we need to remove one variable, either X or Y. Let us remove X in this case. The coefficents of X are 2 and 3. Their lowest common multiplte is 6. We can therefore get both values of X to be 6 in both equations in order to remove this variable. 

Multipying the first equation by 3 gives us 6X+3Y=21. Multipying the second gives us 6X-2Y=16.

If we subtract the first question from the second, the X variable will cancel and we are left with the following:

3y-(-2y)=21-16 which simplifies to 5y=5. Didiving both sides by 5 gives Y=1

The value of Y being 1 can now be substitued back into either equation to find the value of X. Let us try the first one.

2x+(1)=7. Subtracting 1 from both sides gives 2X=6. Dividing both sides by 2 gives X=3.

Our answer can be checked by substituting the values we obtatined for X and Y into the second original equation.

3(3)-1=8. 8=8. We have therefore solved this question. 

Arjan P. 11 Plus Maths tutor, 13 Plus  Maths tutor, GCSE Maths tutor,...

9 months ago

Answered by Arjan, a GCSE Maths tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

532 SUBJECT SPECIALISTS

PremiumIgnacio P. GCSE Business Studies tutor, IB Spanish tutor, A Level Spa...
£36 /hr

Ignacio P.

Degree: Aerospace Engineering MEng (Masters) - Bristol University

Subjects offered:Maths, Spanish+ 5 more

Maths
Spanish
Science
Physics
Further Mathematics
Chemistry
-Personal Statements-

“Author of The 3-Step Method to Achieving (under publishing) - APPLIED NEUROSCIENCE & COACHING FOR EXPLOSIVE RESULTS IN MATH, PHYSICS, SPANISH & MORE!”

£22 /hr

Ayusha A.

Degree: BEng electrical and electronics engineering (Bachelors) - Newcastle University

Subjects offered:Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“About me: I am a final year Electrical and Electronic Engineering student at Newcastle University. I took Mathematics, Further Mathematics, Chemistry and Physics as my A-level subjects. I did peer mentoring in university and also have...”

£18 /hr

Bukky O.

Degree: Maths with Finance (Bachelors) - Exeter University

Subjects offered:Maths, Chemistry

Maths
Chemistry

“Hi, I'm Bukky (pronounced book-ee) and my aim is to not only help your child excel in Maths but also hopefully enjoy it too”

About the author

£18 /hr

Arjan P.

Degree: Economic History with Economics (Bachelors) - LSE University

Subjects offered:Maths, Science+ 1 more

Maths
Science
Economics

“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

You may also like...

Other GCSE Maths questions

What is 45% of 60?

Can you run through the quadratic equation(including the sketch and algebra).

There are n sweets in a bag. 6 are Orange, the rest are Yellow. Hannah takes a sweet out of the bag, and eats it, she does this twice. The Probability of Hannah eating two orange sweets is 1/3. Show that n^2 - n - 90 =0, and solve to find the value of n.

What is a good way to remember the sine, cosine and tangent rules of a triangle?

View GCSE Maths tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok