Question

Identify the expression equivalent to 4(x+ x + 7) - 2x+8 - 4 by substituting x = 1 and x = 2.

O A.
6x + 11
OB.
3(x + 7)
OC. 2(3x + 16)
OD.
3x + 16

Answer 1

C. 2(3x + 16)

Explanation:

If we replace x by 1 in the expression, we get:

4(1+ 1 + 7) - 2(1) + 8 - 4 = 4(9) - 2 + 8 - 4 = 38

If we replace x by 2 in the expression, we get:

4(2+ 2 + 7) - 2(2) + 8 - 4 = 4(11) - 4 + 8 - 4 = 44

Then, if we replace x=1 and x=2 on expression A, we get:

6x+11 = 6(1) + 11 = 17

6x + 11 = 6(2) + 11 =23

if we replace x=1 and x=2 on expression B, we get:

3(x + 7) = 3(1 + 7) = 24

3(x + 7) = 3(2 + 7) = 27

if we replace x=1 and x=2 on expression C, we get:

2(3x + 16) = 2(3(1) + 16) = 38

2(3x + 16) = 2(3(2) + 16) = 44

if we replace x=1 and x=2 on expression D, we get:

3x + 16 = 3(1) + 16 = 19

3x + 16 = 3(2) + 16 = 22

Finally, the answer is C, because we get the same answers as in the initial equation