Solve the two simultaneous equations: 2y + x = 8 [A] and 1 + y = 2x [B]

I have labelled the two separate equations A and B so that it is easier to talk about them. There are two ways in which you can do these equations but I am going to explain the method using substitution. As y and x are in both of the equations we can try to eliminate at least one of these unknowns for the moment. So, if we rearrange [B] so that y=2x-1 we can then substitute this value of y into [A]. This will give us: 2(2x-1) + x =8. By multiplying this out we get: 4x-2+x=8 By grouping the x values together: 5x-2=8 Then placing all the unknowns to one side of the equation 5x=10 and then dividing both sides by 5 we get: x=2. So we have found the value for x! We would then substitute this into [B]: 1+y=2(2),then multiplying this out 1+y=4, placing all the unknowns onto one side: y=3 So we have a solution for y! Just to check that our answers are correct we can substitute our two values into [A]: 2(3)+(2)=6+2 =8 and 8 is the correct answer so we know our solutions are correct!

CD
Answered by Ciara D. Maths tutor

7256 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

a) Find the area of a semi circle with diameter 12cm. b) The area of a semi-circle is 60cm^2. Find the radius of the sem-circle.


A particle is moving along a straight line. The fixed point O lies on this line. The displacement of the particle from O at time t seconds is s metres where s = 2t3 – 12t2 + 7t(a) Find an expression for the velocity, v m/s, of the particle at time t.


Calculate the mean value of 34,35,36,32,39.


The line l is a tangent to the circle x^2 + y^2 = 40 at the point A. A is the point (2, 6). The line l crosses the x-axis at the point P. Work out the area of triangle OAP.


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:

© 2025 by IXL Learning