Question

What is the value of the expression below when z=7 ?


3z−3 ​​

Answer 1

19

Explanation:

First you plug in the 7

3(7)-3

which equals

21-3

this equals 19

Answer 2

18

Explanation:

We have the expression

3z-3

We know that z=7. Therefore, we can substitute 7 in for z.

z=7

3(7)-3

Now, solve according to PEMDAS (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction)

Multiply 3 and 7 first.

21-3

Subtract 3 from 21.

18

The value of 3z-3 when z=7 is 18