Question

Create and solve TWO systems of your own.One must be where you initially substitute anexpression for y and the other must be whereyou initially substitute an expression for x.

Answer 1

Equation 1: 3x + 2y = 7

Equation 2: 2x + 7y = 16

First we solve the first equstion for x:

3x + 2y = 7

3x = 7 - 2y

x = (7 - 2y)/3

Now we take this expression of x and use it into the equation 2:

2x + 7y = 16

2(7 - 2y)/3 + 7y = 16

(14 - 4y)/3 + 7y = 16

Multiplying all by 3 to remove the 3 that is dividing part of the equation:

(14 - 4y) + 21y = 48

14 - 4y + 21y = 48

17y = 48 - 14

17y = 34

y = 34/17

y = 2

Now we use this value on the expression we found for x:

x = (7 - 2y)/3

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

x = (7 - 4)/3

x = 3/3

x = 1

We found the solution by substitution:

x = 1

y = 2