Which of the following is the solution to the equation 25(z + 4) = 125 ?

Question

Which of the following is the solution to the equation 25(z + 4) = 125 ?
Select one:
A. z = 5.5
B. z = 3.5
C. z = -2.5
D. z = -0.5

Answer 1

There are two ways to do this:

 

1) Substitute each answer choice into the equation and see if the equation is satisfied.

2) Use algebra to find the value of z.

 

 

We will use option 2 for the sake of learning how to solve equations such as these.

 

 

Divide both sides of the equation by 25 to isolate the (x + 4) term.

 

z + 4 = 5

 

 

Subtract 4 on both sides of the equation.

 

z = 1

 

Answer 2

Distribute 25 into (z+4).

25(z+4) = 25*z + 25*4 = 25z + 100

Therefore,
25z + 100 = 125.
       - 100    -100

25z = 25

Divide both sides by 25 and get z = 1.
I don't see the right choice among the answers you gave, so there must be some of the mistake from whoever wrote the question.