Solve 2x+y=6, 3x+2y=3 for x and y.

Give each equation a label:(1) 2x+y=6(2) 3x+2y=3Multiply one equation to make the number of x's or y's the same in each equation. 2 X (1) : 2(2x+y=6) 4x+2y=12 (2) 3x+2y=3There are now 2y's in each equation therefore will cancel each other out in next sum.Either add or subtract one equation from other depending of signs of equal letters (in this case y), if signs are the same, (eg. +2y and +2y) then subtract ( eqn (1) - eqn (2) ). If the signs are different (eg. +2y - 2y) then add ( eqn (1) + eqn (2) ). In this case the signs are the same therefore we will subtract. 2 X (1): 4x+2y=12 -(2) - 3x+2y=3, x =9Substitute x=9 into equation (1): 2x+y=6 2(9)+y=6 18+y=6 y=6-18 y=-12Substitute x and y values into equation (2) to check answer is correct:3x+2y=3LHS= 3(9)+2(-12) 27-24 3RHS=3Therefore LHS=RHS, so we know that x=9 and y=-12.

Answered by Emily W. Maths tutor

3437 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations: a) 2x + y = 18, b) x - y = 6


If a line t (f(x) = 2x +3) is perpendicular to a line n that passes through point (3,7), what is the equation of line n?


ABC is an acute-angled triangle. BA=7cm and BC=8cm. The area of triangle ABC is 18 cm^2 . Work out the size of angle BAC. Give your answer correct to 3 significant figures. You must show all your working.


Solve the equation: (2x+3)/(x-4)-(2x-8)/(2x+1)=1


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo
Cookie Preferences