Question

Please help me quickly and explain your answer

Answer 1

A
`x=4`

Explanation:

Perimeter = the sum of all side lengths

Perimeter =
`(x-3)+2x+6`

Perimeter = 15 (in this case)

so...

`(x-3)+2x+6=15`

And we're trying to solve for x.

Step 1. Subtract 6 to both sides

`(x-3)+2x=9`

Step 2. Add 3 to both sides

`x+2x=12`

Step 3. Combine like terms

`3x=12`

Step 4. Solve for x

`x=(12)/(3)`

`x=4`