Solve the simulaneous Equations: 5x + y = 21, x - 3y = 9

Steps to solve a simultaneous Equation:1) Make x and y coefficients the same2) Subtract or add (of which depends on scenario) equations to eliminate x or y3) Solve remaining variable4) Plug into other equation to find x or y(1) 5x+y=21(2) x-3y=9 ---------- (Multiply (2) by 5)5x + y = 215x - 15y = 45----------- (1)-(2)0 +16y = -24, y = -1.5----------- (Plug -1.5 into y in equation (1))5x - 1.5 = 215x = 22.5x = 4.5

TT
Answered by Tait T. Maths tutor

2772 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Work out the value of 2^14 ÷ (2^9)^2


Rationalising the denominator (Surds)


What is the solution to the system of equations defined by (1) x+2y = 4 and (2) y+2x = 6?


What is 2/3 + 1/4?


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