Solve the simultaneous equation, 3x + y = 8 and x + 3y = 12, to find a value for x and y.

Re arrange one of the equation to get a single variant answer. So, x = 12 - 3y. Substitute this into the other equation, so 3 (12-3y) + y = 8. Expand this equation to form 36 - 9y + y = 8. Collect the y terms of the equation on one side, 8y = 28. Re arrange to get y = 28/8. Substitute this into the original equation x = 12 - 3y to get x = 12 - 3 (28/8), to get x = 12 - 84/8. Thus x = 12- 84/8 and y = 28/8.

GR
Answered by Grace R. Maths tutor

6002 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A circle C1 has a centre at (3,0) and a radius 8. A second circle C2 has a centre (x,0) and radius 6. Given the radii of the 2 circles meet at right angles. Find x


Solve the following simultaneous equation: x^2 + y^2 = 9 X+y=2


Solve the simultaneous equations: 4x + y = 25, x - 3y = 16


The equation of the line L1 is y=3x–2. The equation of the line L2 is 3y–9x+5=0. Show that these two lines are parallel.


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