Solve the simultaneous equations x + y = 2 and x^2 + 2y = 12

x+y=2 (1) x2+2y=12 (2) As we are dealing with x2 we’re going to have to use substitution to solve this set of simultaneous equations. From the first equation, we can rearrange to make y the subject: y=2-x (3)Now, we can substitute our new equation (3) into equation (2) to eliminate y: x2 + 2(2-x) = 12. By expanding we get: x2 + 4-2x = 12. To solve for x we need to make the equation equal to 0: x2-2x-8=0. To factorise, we need 2 numbers that multiply to make -8 and add to make -2; these 2 numbers are -4 and 2. Therefore x2-2x-8=0 is equal to (x-4)(x+2)=0. Solving for x we get x=4 and x=-2. We can now substitute these into our equation (3) to find y: y=2-4=-2 and y=2-(-2)=4. So our 2 pairs of answers are: x=4, y=-2 and x=-2, y=4

AK
Answered by Ayesha K. Maths tutor

5710 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Given the ratio of x : y is 7 : 4 and x + y = 88. Work out the value of x – y


What is the equation of the tangent of the circle x^2+y^2=25 at the point (3,4)


What is the photoelectric effect? (A-Level Physics)


John ran a race at his school. The course was measured at 450m correct to 2sf and his time was given at 62 econds to the nearest second. Calculate the difference between his maximum and minimum possible average speed. Round you answer to 3sf.


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