Answer:
x = 8
length is 12 meters
width is 9 meters
Step-by-step explanation:
P = 2l + 2w
where l is the length and w is the width.
(There are two sides with the same length, and two sides with the same width.)
Let l = x + 4 and w = 2x - 7
so 2(x+4) + 2(2x-7) = 42
Distribute the 2s
2x + 8 + 4x - 14 = 42
Combine like terms
2x + 4x + 8 - 14 = 42
Group
6x - 6 = 42
Add 6 to both sides
6x = 48
Divide 6 on both sides
x = 8
Plug back in
l = 8 + 4 = 12 meters
and w = 2(8) - 7 = 16 - 7 = 9 meters
Double-check: 2 * 12 + 2 * 9 = 24 + 18 = 42
