<PRE><B>Question 1194908</B>
 The formula for the surface area is given by s={6r^2}+6rh
:
 a. make h the subject of the relation
6r^2 + 6rh = s
Factor out 6r
6r(r+h) = s
r + h = {{{s/(6r)}}}
h = {{{s/(6r)}}} - r
:
 b. find h if r=2 and s=100 
h = {{{100/(6*2)}}} -2
h = {{{100/12}}} - 2
h = 8{{{1/3}}} - 2
h = 6{{{1/3}}}
:
:
See if this checks out in the original formula; r=2 and h=6.3333
s = 6(2^2) + (6*2*6.3333)
s = 24 + 75.9996
s = 99.9996 ~ 100</PRE>