Which equation has the solution −39? A. x over 3 + 4 = 9 B. -x over 3 − 4 = 9 C. -x over 3 + 4 = 9 D. x over 3 − 4 = 9

Question

A- x/3+ 4 = 9

B- -x/3 - 4 =9

C- -x/ 3 +4 =9

D- X/3 - 4= 9

 I think it's B..

Answer 1

Let's check your selection:

-(-39)/3 - 4 = 9

13 - 4 = 9

9 = 9

 

No you can check solutions in the same manner.

Answer 2

you are correct.

 

-x/3 - 4 = 9

 

-x/3 = 13 <--- adds 4 to both sides

 

-x = 39

 

x = -39

 

Optionally, you can plug -39 into each of the options to see which one works.

 

-(-39)/3 - 4 = 39/3 - 4 = 13 - 4 = 9

 

Notice that the other choices do not work:

 Option A)   -39/3 + 4 = -13 + 4 = -9    <--- choice A does not work

 

 Option C)  -(-39)/3 + 4 = 39/3 + 4 = 13 + 4 = 17

 

 Option D)  (-39)/3 - 4 = -13 - 4 = -17 

choices C and D do not work