Answer:
20 cm
Step-by-step explanation:
Shadow of vertical poles : 6m ; 15m
Length of poles : 8cm ; h
8cm long pole = shadow length, 6m
h cm long pole = shadow length, 15 m
Using cross multiplication :
8cm * 15 m = h cm * 6m
120 = 6h
h = 120 / 6
h = 20 cm
Height of second pole = 20cm
Step 4 is wrong. the answer is 1/8, she changed sign on 2^(-3) to 2^(3) without moving it to numerator
6x - 11 + 15x + 2 = 180
21x - 9 = 180
21x = 189
x = 9
—
D = 15(9) + 2
D = 135 + 2
D = 137