How do you solve simultaneous equations?

I will run through an example of how to solve a set of simultaneous equations. In simultaneous equations you are given two or more algebraic equations and you need to solve them for the variables, usually called x and y. You start off by trying to get equivalent coefficients for either the x or y value in both of the equations.  For example: (1) 4x + y = 24 and (2) 7x + 3y = 47. Here we can multiply equation (1) by 3 so that both the x coefficients are equal to 3. So 3*(1) is equivalent to 12x + 3y =72. Now we can subtract (2) from 3*(1). This gives 5x + 0y = 25, giving 5x = 25 therefore x = 5. Substituting x back into equation (1) we get 4*5 + y =24. So y = 24 - 20 and y = 4. Giving us the solutions: x=5 and y=4.

DH
Answered by Dorothy H. Maths tutor

3634 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

f(x) = x^2 + 2x - 3. Where does the graph of the function f intersect the x-axis?


How can I tell if two lines are perpendicular from the equations?


Solve 3x2 + 7x – 13 = 0 Give your solutions correct to 2 decimal places.


Given that y r 1 2 x , complete this table of values. x 1 2 5 10 y 1


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