Solving for a specified variable (details)

Please include each step, that way I'll learn how to solve them. Thank you (:

a) S = 2 π r h + 2 π r^2 solve for h

b) 4s + 7p = tp - 7 solve for p

CORRECT ANSWERS:
a) h = S - 2 π r^2 over 2 π r
b) p = 4s + 7 over t - 7

S= 2πrh +2πr²

2πrh=S-2πr²

h= (S-2πr²)/(2πr)
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4s+7p=tp-7

tp-7p=4s+7

(t-7)p=4s+7

p=(4s+7)/(t-7)

a) Just isolate h... S - 2 π r ^2 = 2 π r h ... now divide each term by 2 π r and find h

h = ( S - 2 π r ^2 ) / 2 π r ... OK! ... the answer is correct.

b) Just isolate p... 4s + 7 = tp - 7p... put p in evidence.... p(t-7) = 4s + 7 ... now divide each term by (t-7) .... then p = (4s+7)/(t-7) ... OK.... the answer is correct.

a) S = 2 π r h + 2 π r^2 solve for h

- 2 π r h = 2 π r^2 - S

h = (2 π r^2 - S)/(- 2 π r)

h = (S - 2πr^2)/(2πr)

b) 4s + 7p = tp - 7 solve for p

7p - tp = - 4s - 7

p(7 - t) = - 4s - 7

p = (- 4s - 7)/(7 - t)

p = (4s + 7)/(t - 7)