how wod i rearrange the following formulae to make each of the requested letters the subject:?

Question

a) 1 / v = 1 / u1 + 1 / u2 , find u1

b) 3^x = A, find A

c) s = ut + 1/2 (half) at^2, find a

Answer 1

Question a)
1 / u1 = 1 / v - 1 / u2
1 / u1 = (u2 - v) / (v u2)
u1 = (v u2) / (u2 - v)

Question b)
A has already been found.
Find x?
ln (3^x) = ln A
x ln 3 = ln A
x = ln A / ln 3

Question c)
s = u t - (1/2) a t ²
(1/2) a t ² = u t - s
a t ² = 2 (u t - s)
a = (2 / t ²) (u t - s)

Answer 2

a) u1 = {(vu2)/(u2-v)}

b) A = 3^x

c) a = {2(s-ut)/t2)}