The formula for perimeter is P=2l+2w where P is perimeter, l is length and w is width. P=54 inches and l is 15 inches but we do not know the value of w. Let's replace the letters with their number P=2l+2w 54=2(15)+2w 54=30+2w let's group like terms or numbers that are similar. 54 and 30 have no letters attached to them and so are the similar. So let's move 30 to the right side. Since 30 is positive on the right side, subtract it from both sides of the equation. 54-30=30+2x-30 24=2w 24/2=2w/2 12=w Therefore the width is 12 inches.
