MYTUTOR SUBJECT ANSWERS

526 views

How do you solve a simultaneous equation?

Example question:

Solving Simultaneous Equations

Equation 1: 6x + 2y = 2
Equation 2: 5x - 7y = 6.
Find x and y.

1) Check is if it is possible to solve. Here we have 2 unknowns, x and y, and 2 equations, therefore it is possible to solve. (If there are more unknowns than equations then it is not possible to solve.)

2) Eliminate an unknown in one of the equations.

- Rearrange each equation to get the x terms on one side and the y terms on the other.

Eq 1 .... 6x=2-2y
Eq 2 .... 5x=6+7y

- Look for a common multiple for the coefficients (number in front of the unknown) of x, e.g. 30. So we multiply each equation up to get 30x on one side, then we can say equation 1 equals equation 2.

5 x Eq 1 .... 30x=10-10y .... we will call this Eq 3
6 x Eq 2 .... 30x=36+42y .... we will call this Eq 4

- Remember what you do to one side of the equation you must do to the other.

3) Now both Eq3 and Eq4 are of the form 30x=.... we can say that Eq3=Eq4.

10-10y = 36+42y

4) Now just solve as you would normally to find y=-0.5.

5) Put this value of y into Eq1 to find x=0.5.

6) Put both these values into Eq2 to check result, e.g. 6*0.5 + 2*-0.5 = 3 - 1 = 2.
This is correct therefore we have the correct answer.

Toby F. GCSE Maths tutor, A Level Maths tutor, GCSE Physics tutor, A ...

2 years ago

Answered by Toby, a GCSE Maths tutor with MyTutor


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

515 SUBJECT SPECIALISTS

£24 /hr

Chloe W.

Degree: Mathematics (Bachelors) - Bristol University

Subjects offered:Maths, Further Mathematics

Maths
Further Mathematics

“About Me:I'm Chloe and I'm a 2nd year maths student at Bristol university. I've always enjoyed working with numbers and I hope that I can encourage others to love working with them too!I've tutored both of my siblings through their...”

£20 /hr

Bryan P.

Degree: Mathematics (Bachelors) - Bristol University

Subjects offered:Maths, Further Mathematics

Maths
Further Mathematics

“I am currently a BSc Mathematics student at the University of Bristol and I am already no stranger to teaching.I have worked as a teaching assistant in my secondary school's maths department where I also led one-on-one sessions with ...”

£18 /hr

Jacob M.

Degree: History (Bachelors) - Manchester University

Subjects offered:Maths, History+ 1 more

Maths
History
Geography

“Tutoring experience I have gained three years tutoring experience with five seperate students of different ages and capabilities on a one-to-one basis. The subjects I have tutored include Maths, Biology, Physics and Chemistry at GCSE ...”

About the author

Toby F.

Currently unavailable: until 20/09/2015

Degree: Mechanical Engineering (Masters) - Durham University

Subjects offered:Maths, Physics+ 1 more

Maths
Physics
Further Mathematics

“I'm Toby, a fourth year Engineering Masters undergraduate at Durham University. I want to share my enthusiasm for maths and science, tutoring at GCSE and A-Level standard.”

You may also like...

Other GCSE Maths questions

How do you calculate the hypotenuse of a right angle triangle if the two shorter sides are 6 and 8?

How to add fractions

How Would I Factorise A Quadratic Equation?

Solve the equations giving your answer in 2d.p (5 Marks).: x^2 + y^2 = 36 , x = 2y + 6

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