Question

Solve the following system of equations using substitution, showing all work.

y=2x+3
2x+5y=3

Answer 1

x=negative 1

y=1

showing my work Substitute y=2x+3y=2x+3 into 2x+5y=32x+5y=3.

12x+15=312x+15=3

2 Solve for xx in 12x+15=312x+15=3.

x=-1x=−1

3 Substitute x=-1x=−1 into y=2x+3y=2x+3.

y=1y=1

Answer 2

x= -1

y= 1

Explanation:

since y=2x+3; plug into other equation

2x+5(2x+3)=3

(distribute 5 to 2x+3)

2x+10x+15=3

(add like terms)

12x= -12

divide by 12 to get x alone

x=-1

now you cand plug in x to either equation to solve for y, but plug into the first equation to make it easier.

y=2(-1)+3

y=-2+3

y=1