MYTUTOR SUBJECT ANSWERS

198 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,...

5 months ago

Answered by Arjan, a GCSE Maths tutor with MyTutor


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

434 SUBJECT SPECIALISTS

£18 /hr

James T.

Degree: Chemical Engineering (Masters) - Bath University

Subjects offered: Maths, Physics+ 2 more

Maths
Physics
Chemistry
-Personal Statements-

“About me: I am in my second year of Chemical Engineering at the University of Bath. I love problem-solving and hard work! I recognise that everyone works differently so I will try to find the best way for you to learn! I am very frien...”

MyTutor guarantee

£18 /hr

Sahil M.

Degree: Medicine (Bachelors) - Manchester University

Subjects offered: Maths, Spanish+ 3 more

Maths
Spanish
Chemistry
Biology
-Medical School Preparation-

“Hello! My name is Sahil and I am currently a medical student at the University of Manchester. I am really looking forward to tutoring you in Spanish, Chemistry, Biology or Maths as well as trying to help you during the difficult proce...”

£20 /hr

Hannah O.

Degree: Physics (Masters) - Warwick University

Subjects offered: Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“Hello! My name's Hannah and I am currently studying Physics at the University of Warwick. As a lifelong enthusiast, I understand how wibbly-wobbly physics can get at times. It can be tricky to wrap your head around all of the formulae...”

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 are the values of x and y?

What is "Standard Form"?

Solve 5x^2 - 9x + 4 = 0 using the quadratic formula

How would I solve x^2 + 7x + 10 = 0

View GCSE Maths tutors

Cookies:

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

mtw:mercury1:status:ok