Question

Solve by substitution -x+y=7 and 2x+3y=31

Answer 1

Answer:

(2,9)

Step-by-step explanation:

To do this you have to solve one of the equations for a variable.

-x+y=7

2x+3y=31

Because the first equation doesn't have any numbers attached to the variables I decided to solve for the y in that equation.

-x+y=7

y=x+7

With this now one would have to plug this into the second equations:

2x+3(x+7)=31

Use the distributive property.

2x+3x+21=31

simplify.

5x+21=31

Isolate the x.

    -21     -21

5x=10

solve for the x.

x=2

Plug the x into one of the equations and solve for y.

-x+y=7

-2+y=7

isolate the y.

+2     +2

y=9

This  is the point of solution.