What is the total surface area of a cylinder if its radius is x + 2 and its height is x + 5?

Question

anonymous · Answer

if it is a closed cylinder ,then surface area=area of curved surface+circular area of top+circular area of bottom.

anonymous · Answer

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anonymous · Answer

I know how to find the area of a cylinder, I just don't know how to do it with binomials :(

anonymous · Answer

$$curved~surface=2\times \pi \left( x+2 \right)\left( x+5 \right)$$
simplify it.

anonymous · Answer

6.28(x^2 +7) ?

anonymous · Answer

$$=2\pi \left( x^2+2x+5x+10 \right)=2\pi \left( x^2+7x+10 \right)$$

anonymous · Answer

ooohhhhhhhh  ok!  that's the surface area of the curved surface?  Or the whole thing?

anonymous · Answer

surface area of base and top=2*(pi r^2)
$$=2 \pi \left( x+2 \right)^2$$
now find total surface area by adding the two .

anonymous · Answer

so 2*3.14(x^2 + 7x + 10)  +  2*3.14(x + 2)^2

anonymous · Answer

4*3.14^2(x^3 + 7x + 12)