If x+2y=100 and 3x+2y=180, what is x and y?

Answer 1

You have two equations and two unknowns, a and y.

3x + 2y = 180

x + 2y = 100

You have multiple ways to solve two equations and two unknowns. The easiest way for these equations is to multiply the second equation by -1 and then add the two equations to eliminate the y terms.

3x + 2y = 180

-x - 2y = -100

____________

2x = 80

x = 40

Then, we can pick either of the original equations and solve for y since we know that x = 40. I pick the second equation.

2y = 100 - x

y = 50 - x/2

y = 50 - 40/2

y = 50 - 20

y = 30

So, x = 40 and y = 30

Answer 2