In Heather's physics class, she had to solve the equation 7=12at2+ut for u.
Which equation correctly solves for u?

Answer:
B (7 -1/2 at^2)/t = u
Step-by-step explanation:
7 = 1/2 at^2 + ut
subtract 1/2 at^2 from each side
7 -1/2 at^2 = 1/2 at^2 + ut - 1/2 at^2
7 -1/2 at^2 = ut
divide by t
(7 -1/2 at^2)/t = ut/t
(7 -1/2 at^2)/t = u