Question

What is the solution to the system of equations x+3y=15 and 4x+2y=30

Answer 1

@VCabral1134 @lyssa577 @Ashleyrh1999

Answer 2

x + 3y = 15
x = -3y + 15

so sub in -3y + 15 in for x in the other equation.

4x + 2y = 30
4(-3y + 15) + 2y = 30 --- distribute through the parenthesis
-12y + 60 + 2y = 30 -- simplify
-10y + 60 = 30 --- subtract 60 from both sides
-10y = 30 - 60
-10y = -30 -- now divide both sides by -10
y = 3

x + 3y = 15....now sub in 3 for y and find x
x + 3(3) = 15
x + 9 = 15 -- subtract 9 from both sides
x = 15 - 9
x = 6

now we can check our answers...
4x + 2y = 30
4(6) + 2(3) = 30
24 + 6 = 30
30 = 30 (correct)

so x = 6 and y = 3