how do you solve these simultaneous equations?

6x + y = 8 (1)       4x - y = 12 (2)

 

Method 1 elimination:

-Adding/subtracting the two equations together to eliminate one of the unknowns 

 (1) + (2)

  6x + y = 8

+  4x - y = 12

10x = 20        (/10)

x= 2

sub 'x=2' into (2)

4(2) - y = 12

8 - y = 12      (+y) 

8 = 12 + y     (-12)

-4 = y

Method 2 substitution:

-rearranging one of the equations to make an unknown the subject 

rearrange (2)

4x - y = 12 

4x = y + 12      (+y)

y= 4x - 12        (-12)

sub 'y = 4x - 12' into (1)

6x + '4x - 12' = 8

10x - 12 = 8        (+12)

10x = 20

x = 2

sub 'x=2' into 'y = 4x - 12'

y = 4(2) - 12 

y = 8 - 12

y = -4

SG
Answered by Shriya G. Maths tutor

5326 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

There are 10 boys and 20 girls in a class. The class has a test. The mean mark for all the class is 60. The mean mark for the girls is 54. Work out the mean mark or the boys.


Use factorisation to simplify the following expression (x^2-9)/(x^2-4x+3)


Factorise and solve x^2 - 8x + 15 = 0


ABCD is a regular paralleogram, A=(2,1) B=(7,2) and C=(4,6), work out the gradient of the line CD and then work out the area of ABCD.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning