9514 1404 393
Answer:
A) P = 8d +14
B) d = 2
C) 56 cm^2
Step-by-step explanation:
A) The perimeter is the sum of all of the side lengths.
P = 2(L +W)
P = 2((3d +2) +(d +5)) = 2(4d +7)
P = 8d +14
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B) Using 30 for P, we have ...
30 = 8d +14
16 = 8d . . . . . . . subtract 14
2 = d . . . . . . . . . divide by 8
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C) The side lengths are ...
3d +2 = 3(2) +2 = 8 . . . . cm
d+5 = 2+5 = 7 . . . . cm
Then the area is ...
A = LW
A = (8 cm)(7 cm) = 56 cm^2
The area of the rectangle is 56 square centimeters.