Question

Keith writes an expression using the following steps: Start with x, multiply by -2, subtract 7, and subtract 12. He wrote the final expression -2(x - 7) - 12. Explain what he did wrong. Then write the correct expression.

Answer 1

Including the paranthesis (brackets) in the expression.

-2x - 7 - 12

Step-by-step explanation

Keith wrote the expression:

-2(x - 7) - 12

Let us write the correct expression and then compare to find what he did wrong.

Start with x:

x

Multiply by -2:

-2x

Subtract 7:

-2x - 7

Subract 12:

-2x - 7 - 12

As we can see, the mistake that Keith made was including the paranthesis (brackets) in the expression.