Question

what is Peter's number? if you subtract 12 from my number and multiply the difference by -3 the result is -54

Answer 1

Let "x" represent the number.

You have to subtract 12 from that number

`x-12`

Then, multiply the difference by -3

`-3(x-12)`

The result must be -54

`-3(x-12)=-54`

From this expression, you can calculate the value of x:

First, distribute the multiplication on the parentheses term, that is, multiply both terms by -3:

`\begin{gathered} (-3)\cdot x-(-3)\cdot12=-54 \\ -3x-(-36)=-54 \\ -3x+36=-54 \end{gathered}`

Second, subtract 36 from both sides of the equal sign:

`\begin{gathered} -3x+36-36=-54-36 \\ -3x=-90 \end{gathered}`

Third, divide both sides by -3

`\begin{gathered} (-3x)/(-3)=(-90)/(-3) \\ x=30 \end{gathered}`

Peter's number is 30.