How do you solve the following system?: 2x+3y=-5 , y=2x+9 2x+3y=5,y=2x+9

1 Answer
May 6, 2018

x=-4, y=1x=4,y=1

Explanation:

  1. 2x+3y =-52x+3y=5
  2. y=2x+9y=2x+9

Equation 2 already has yy as the subject of the equation, substitute that in place of the yy in the first equation.

2x + 3(2x+9) = -52x+3(2x+9)=5

Simplify the equation and calculate the value of xx.

2x+6x+27 = -52x+6x+27=5
8x = -328x=32
x=-4x=4

Then insert that value of xx into equation 2 to find the value of yy.

y=2(-4)+9y=2(4)+9
y=-8+9y=8+9
y=1y=1