What is the value of y in the system of equations shown below? 7x − 7y = 49 3x − 16y = 34 Select one: A. -2 B. -1 C. 0 D. 1

Question

asked Apr 18, 2020 60.2k views

1 Answer

Deryck · Answer 1 · 2020-04-24T21:25:39+0000

Answer:

B. -1

Explanation:

Given

$7x-7y =49\\7(x-y)=49\\x-y =(49)/(7)\\x-y= 7 \ \ \ \ equation \ 1$

$3x- 16y = 34 \ \ \ \ equation \ 2$

Now multiplying equation 1 with 3 on both side we get,

$3* (x-y)= 3 * 7\\3x-3y=21 \ \ \ \ \ equation \ 3$

Now Subtracting above equation 3 from equation 2 we get.

$-13y=13\\y= -1$