Question

using algebra to solve word problems w/ perimeter - google slides
example 2
the length of a rectangle is three centimeters less than twice its width. if the perimeter of the rectangle is 18 centimeters, find its dimensions.
14 multiple - choice question
what is the first step in solving the equation?
subtract 2w from both sides.
divide both sides of the equation by 2.
distribute (open the parentheses).
combine like terms.
rewatch

Explanation:

Step1: Identify the equation

The perimeter formula for a rectangle is $P = 2L+2W$. Given $L = 2W - 3$ and $P=18$, we substitute to get $18=2(2W - 3)+2W$.

Step2: Determine the first - step

The first step in solving $18 = 2(2W - 3)+2W$ is to distribute the 2 in $2(2W - 3)$ according to the distributive property $a(b + c)=ab+ac$. So we open the parentheses.

Answer:

Distribute (open the parentheses).