I have some problems that I don't understand. Please help me.

Solve the formula for the specified variable.

s=2ðrh + 2ðr^2 for h

f= (9/5)c+32 for c

A=P(1+nr) for r

for H i don't know what that notation is so I'll leave that alone and maybe someone else can help you with that

for c, there won't be a definite number but rather another function.

f=(9/5)c+32
f-32= (9/5)c divide over to get c
(f-32)/(9/5)= c

-just flip 9/5 and multiply it to f-32 (I'll leave that to you (If you need help just ask and I'll be glad to =D )

~for r

A=P(1+nr)
A/P= 1 + nr
(A/P)-1= nr
[(A/P)-1]/n= r