Question

Slove by using elimination 3x+7y=27 -3x+y=21

Answer 1

Answer:

x = -5

y = 6

Step-by-step explanation:

3x + 7y = 27      --------------(I)

-3x + y = 21        -----------(II)

Add equation (I) & (II) and so x will be eliminated and we can find the value of y.

(I)      3x + 7y = 27    

(II)     -3x + y = 21        {add}

                8y = 48

                   y = 48/8

                   y = 6

Plugin y = 6 in equation (I)

3x +7*6 = 27

3x + 42 = 27

       3x = 27 - 42

       3x = -15

         x = -15/3

x = -5