Answer:
x=3
Step-by-step explanation:
5x+6=21
5x=15
x=3
Answer: I don't know
Step-by-step explanation:
There are no choices. The question stated choose the polynomial which means it should have choices.
Correct me if I'm wrong though. Hope you won't be offended.
Answer:
1920 ft³
Step-by-step explanation:

Area = 625 cm^2
Area = s^2
Diagonal = s*sqrt(2)
625 = s^2
s = sqrt(625)
s = 25 cm.
Diagonal = s*sqrt(2)
= 25sqrt(2)
=35.36 cm.
=35.4 cm.