Question

Solve the following system by using substitution-3x+6y=15y=2x+4

Answer 1

-3x + 6y = 15 -----------------------(1)

y = 2x + 4 -----------------(2)

substitute equation 2 in (1) and then solve for x

-3x + 6(2x + 4) = 15

-3x + 12x + 24 = 15

9x + 24 = 15

subtract 24 from both-side

9x = 15 - 24

9x = -9

Divide both-side of the equation by 9

9x/9 = -9/9

x = -1

substitute x = -1 into equation (2)

y = 2(-1) + 4

y = -2 + 4

y = 2