Question

http://prntscr.com/90qlzj
http://prntscr.com/90qn38

Answer 1

@bibby

Answer 2

replace the unknowns with the given numbers
\(\color{green}{S}=4 \color{red}{\pi} r^2\\\color{green}{S=500}\\\color{red}{\pi = 3.14}\)

Answer 3

so it would be 500 = 4*3.14r^2

Answer 4

yep. then we divide both sides by 4 and 3.14 (or 4*3.14) to get \(r^2\) alone on one side. from there we take the square root of both sides to just get r

Answer 5

so we're dividing by 4*3.14?

Answer 6

yeah, or you can do it in 2 steps and divide by 4
then divide by 3.14

Answer 7

im done with that equation

Answer 8

so you have the answer?

Answer 9

i meant i got r^2 alone

Answer 10

ah \(500=4*3.14r^2\\\dfrac{500}{4*3.14}=r^2\)
now we take the square root of both sides

\(39.8=r^2\\
\sqrt{39.8}=r\\r \simto 6.3\)

Answer 11

\(r\sim 6.3\)

Answer 12

so were done with this question right

Answer 13

yeah
part 2 now

Answer 14

alright

Answer 15

let's do one with Celsius/Fahrenheit
\(F=\dfrac{9}{5}C+32\)
Find the Fahrenheit equivalent temperature of \(100C\)

I think something like that would work

Answer 16

yeah it would

Answer 17

let's do something with the volume of a cylinder. \(v=\pi r^2 h\)

if we have \( \pi = 3.14\\
r=4
\\h=?
\)

Answer 18

is this going to be part of the question above?

Answer 19

nah this is the 2nd one

Answer 20

lets finish the first one first then do the second one

Answer 21

\(F=\dfrac{9}{5}C+32\) Find the Fahrenheit equivalent temperature of 100C
\(F=\dfrac{9}{5}100+32\\F=9(20)+32=180+32=212F\)

Answer 22

done

Answer 23

let's try #2 now
\(v=\pi r^2 h\\V=400\\r=3\\\pi=3.14\)

Answer 24

you'd have to write up a little sentence for the "word problem" part

Answer 25

got it

Answer 26

when we calculate 400cm^3 = 3.14*3^2*h whatsthe height?