Solve the following simultaneous equation: 3x+2y=20 and x+4y=20

We are going to try to eliminate one of the variables in one of the equations. This can be done by rearranging the second equation to x=20-4y. And then substituting x into the first equation.3x+2y=20 => 3*(20-4y)+2y=20 => 60-12y+2y=20 Then we separate constants and variables:=> -10y=-40 => y=(-40)/(-10) => y=4We have found y! Now it's easy to find x, using the equation x=20-4y => x=20-4*4 => x=4So the numbers which satisfy the two equations simultaniously are x=4 and y=4.

Answered by Stephanie K. Maths tutor

4793 Views

See similar Maths 13 Plus tutors

Related Maths 13 Plus answers

All answers ▸

11(x+3)=121


solve the following equation: x^2 - 7x -15 = 3


One apple costs 0.56p, if i wanted 12 Apples what would be my total?


At the shop, Max buys 5 juice boxes and 12 sweets which costs him £1.34 in total. If x represents the cost of one juice box (in pence) and y represents the cost of one sweet (in pence), write out an equation, in terms of x and y, to show this


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