Answer:
B. 15 inches.
Step-by-step explanation:
A rectangle shares two pairs of congruent opposite sides.
Perimeter = 42
Let:
the length of the rectangle = l
the width of the rectangle = w = 6
Perimeter = l + l + w + w
Plug in 42 for perimeter & 6 for w in the equation:
42 = l + l + 6 + 6
Combine like terms:
42 = ( l + l ) + (6 + 6)
42 = 2l + 12
Next, isolate the variable, l. Do the opposite of PEMDAS. First, subtract 12 from both sides:
42 (-12) = 2l + 12 (-12)
42 - 12 = 2l
30 = 2l
Next, divide 2 from both sides:
(30)/2 = (2l)/2
l = 30/2
l = 15
B. 15 inches is the length of the rectangle.
Check:
l + l + w + w = 42
15 + 15 + 6 + 6 = 42
30 + 12 = 42
42 = 42 (True).
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