Solve the simultaneous equations to find x and y: 2x - 2y = 20, x + 4y = 5

Equation1: 2x - 2y = 20, equation 2: x + 4y = 5First method (subtraction):Multiply equation1 by 2: 4x - 4y = 40Add the two equations together canceling out the y unknowns: 4x + x = 40 + 5Solve for x: 5x = 45, therefore x = 9Plug the value for x into equation2 and solve for y: 9 + 4y = 5, therefore y = -1Second method (substitution):Arrange equation2 to have x on one side and everything else on the other by subtracting 4y from both sides: x = 5 - 4ySubstitute this equation for x into equation1 and solve for y: 2(5 - 4y) - 2y = 20, therefore 10 - 10y = 20, therefore -10y = 10, therefore y = -1Plug the value of Y into equation2 and solve for x: x - 4 = 5, therefore x = 9

JS
Answered by John S. Maths tutor

5422 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Factorise 2x^3=10x+12x^2


Solve the following simultaneous equations: (1) 3x – 2y = 7 (2) 5x + 2y = 17


If a student wishes to have a ratio of 2:7 red pens to yellow pens in their pencil case: a) if they have 50 pens total what is the maximum amount they can carry with them b) if they have 18 red and 31 yellow what is the maximum amount they can carry


Solve for x 2x +3 + (4x-1)/2 = 10


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