The perimeter P of a rectangle is P = 21 + 2w, where I and w are the rectangle's length and width, respectively.
(A) Rewrite the formula to find the length given perimeter and width. Justify each step in your solution with the property used. (B) compite the length of a rectangle with a perimeter 40.2in and width of 6.7in.

see below

Step-by-step explanation:

P = 2l + 2w

Subtract 2w using the subtraction property of equality

P -2w = 2l+2w-2w

P -2w = 2l

Divide each side by 2, using the division property of equality

P/2 -2w/2 = 2l/2

1/2 P -w = l

Now we have P =40.2 and w = 6.7

l =1/2 (40.2) - 6.7

l =20.1-6.7

 =13.4

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x

angle efh= angle egh