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

5489 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Expand and simplify 3(m + 4) – 2(4m + 1)


Express 0.545454... as a fraction in its simplest form.


Raya buys a van for £8500 plus VAT at 20%. Raya pays a deposit for the van. She then pays the rest of the cost in 12 equal payments of £531.25 each month. Find the ratio of the deposit Raya pays to the total of the 12 equal payments.


In a school 2/5 students play an instrument. Of those students 3/7 play the violin. Find the ratio of students who play the violin compared to the students who do not play the violin.


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