Question

Use the substitution method to solve.

Answer 1

Answer:

x = 7, y = 6

Step-by-step explanation:

solve for y for the first equation

2x + y = 20

-2x         -2x , eliminate 2x

y = 20-2x

now that we have found y, substitute the y in for the second equation

-5y = -6x + 12

-5(20-2x) = -6x + 12, we just changed y into 20-2x. remember that we are multiplying all of 20 - 2x by -5

-100+10x = -6x + 12, we multiplied everything from the parathesis  by -5

+100                 + 100, eliminate -100

10x = -6x + 112

+6x    +6x , eliminate 6x

16x = 112 , solve for x

x = 7

then y = 20 - 2x = 20 - 2*7 = 6

check:

2 * 7 + 6 = 20

20 = 20

-5 * 6 = -6 * 7 + 12

-30 = -42 + 12

-30 = -30