Question

Solve system of linear equations by substitution. check your solution. y=3x+4

x+y=8

Answer 1

y = 3x + 4
x + y = 8

Substitute 3x + 4 in for y in the second equation.

x + 3x + 4 = 8

Combine like terms.

4x + 4 = 8

Subtract 4 from both sides.

4x = 4

Divide 4 off of both sides to find the value of x.

x = 1

Now plug 1 into the second equation for x.

1 + y = 8

Subtract 1 from both sides.

y = 7

(1,7) is the final answer.