Question

use the substitution method to solve the system of equations choose the correct orderd pair. 3x-y=7 2x-2y=2

Answer 1

Answer:

(3,2)

Step-by-step explanation:

We are given the system:

3x-y=7

2x-2y=2.

We are asked to solve this by substitution.  We need to pick an equation and pick a variable from that equation to solve for that variable.

I really like either for this.  Some people might go with the first one though. Let's do that.  I will solve the first one for y.

3x-y=7

Subtract 3x on both sides:

   -y=-3x+7

Divide both sides by -1:

     y=3x-7

Now we are ready for substitution.  We are going to plug this equation into the second equation giving us:

2x-2y=2 with y=3x-7 gives us:

2x-2(3x-7)=2

Distribute:

2x-6x+14=2

Combine like terms:

-4x+14=2

Subtract 14 on both sides:

-4x      =2-14

Simplify:

-4x       =-12

Divide both sides by -4:

  x       =-12/-4

Simplify:

 x         =3

So using y=3x-7 and x=3, I will find y now.

y=3x-7 if x=3

y=3(3)-7   (I inserted 3 for x since we had x=3)

y=9-7       (Simplified)

y=2           (Simplified)

The answer is (x,y)=(3,2).