W = H + 4
L = W + 8 = H + 4 + 8 = H + 12
A = 2H (W + L) = 2 H (2H + 16)
512 = 4 H² + 32 H
128 = H² + 8 H
0 = H² + 8 H - 128
solve for H, then substitute back to find W and L
A rectangular room is 4 meters wider than its high and it is 8 meters longer than its wide. the total Ares of the wall is 512 square meters. Find the dimensions of the room.
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