Question

Add the equations. What value belongs in the green box? 3x + 2y = 9 -x - 2y = 4 [?] + [?] = [?] A. 4x B. 2x C. -3x D. -2x​

Answer 1

Consider the first blank is the green box.

Given:

The equations are

$3x+2y=9$

$-x-2y=4$

To find:

The value belongs in the green box

Solution:

We have,

$3x+2y=9$        ...(i)

$-x-2y=4$        ...(ii)

Adding (i) and (ii), we get

$3x+2y-x-2y=9+4$

$(3x-x)+(2y-2y)=13$

$2x+0=13$

So, the value for the first black is 2x. It means the value belongs in the green box is 2x.

The values of three blanks are 2x, 0 and 13 respectively.

Therefore, the correct option is B.