Answer:
The mistake was on your second step where you took b to be +6, yet it has to be -6.
The answer is -13 13/35.
Hope this helps & good luck. :)
B is the answer.
Step-by-step explanation:
13 + (-20) = 13 - 20 = -7
HOPE IT HELPS
Acute angle
final answer will be 937.5 Kgm^2S^2 or 937.5 J
