Question

For the solution (x, y) to the system of equations, what is the value of x − y?

7x + 3y = 8
6x − 3y = 5
A) −
4
3
B)
2
3
C)
4
3
D)
22
3

Answer 1

Answer:

x = 1        y = 1/3

Step-by-step explanation:

STEP 1)  get the equations to equal each other

7x + 3y = 8             6x - 3y = 5

- 7x                              - 6x

3y = 8 - 7x              -3y = 5 - 6x

     *1                              *-1

3y = 8 - 7x       =       3y = -5 + 6x

STEP 2)  solve for x

8 - 7x = 6x - 5

      +7x

8 = 13x - 5

      +5

13 = 13x

    /13

1 = x

STEP 3)  use x to solve for y

7x + 3y = 8

       =

7 + 3y = 8

      -7

3y = 1

  /3

y = 1/3