Find the values of x and y when 3x+4y=18 and 4x+2y=14

Label equations: (a) 3x+4y=18(b) 4x+2y=14We need to be able to cancel out either the x's or the y's. The simplest choice is to double (b) so that we can cancel out the y's.2 x (b) : 8x+4y=28 (Give this a new label, (c))Cancel out the y's by subtracting (a) from (c), (we could do this the other way round but makes sense to take away the smaller numbers as this keeps the equation positive)So we have (c)-(a):8x+4y=28-(3x+4y=18)Which leaves 5x=10 (the y's have cancelled out). Then, dividing both sides by 5, we have x=2.We are not quite done yet, we still need to find out what y is. We do this by substituting our value for x into our original equations. Substituting x=2 into (a) gives:6+4y=184y=12y=3Always check this answer with the other equation (b). Substituting x=2 into (b) gives:8+2y=142y=6y=3 Great! Same answer. So x=2 and y=3.

RE
Answered by Rosie E. Maths tutor

5809 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

What is (18)^1/2 -(8)^1/2 simplified?


Write 16*8^2x as a power of 2 in terms of x.


A is the point with coordinates (1, 3) B is the point with coordinates (–2, –1) The line L has equation 3y = 4 – 2x Is line L parallel to AB?


How do you work out the nth term for a linear equation?


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