Question 126637
Original Width: x
Original Length: 2x + 1
Original Area: (x)(2x + 1)

Increased Width: x + 5 
Increased Length: 5 + 2x + 1
Increased Area: (x + 5)(5 + 2x + 1)

"If each dimension were increased by 5 cm, the area would be at least 150 cm² greater."
(x + 5)( 5 + 2x + 1) ≧ 150 + x + 2x² 
(x + 5)(6 + 2x)≧ 150 + x + 2x² 
(Use FOIL - first, outside, inside, and last to multiply)
30 + 6x + 10x + 2x²≧ 150 + x + 2x² 
30 + 16x + 2x²≧ 150 + x + 2x² 
16x - x ≧ 120
15x≧120
x≧8

Answer: 
Width: 8
Length: 17