Question

Solve SA = 2ab + 2bc + 2ac for b

Answer 1

factor out the b from the first two terms

Answer 2

how?

Answer 3

SA = 2ab + 2bc + 2ac
=b(2a+2c)+2ac

Answer 4

now take away that last term from both sides,
and finally divide both sides of the equation by the factor that leaves only b on the RHS

Answer 5

-2ac=b(2ac+2c?

Answer 6

what does SA stand for?

Answer 7

It should look something like this:


\[\Large SA = 2ab + 2bc + 2ac\]


\[\Large SA = b(2a + 2c) + 2ac\]


\[\Large SA-2ac = b(2a + 2c)\]


\[\Large b(2a + 2c) = SA-2ac\]


What's the last step?

Answer 8

it's part of the problem.

Answer 9

divide by -2ac?

Answer 10

not quite

Answer 11

you have to divide both sides by 2a+2c

Answer 12

So here are the full/complete steps to isolating b:


\[\Large SA = 2ab + 2bc + 2ac\]


\[\Large SA = b(2a + 2c) + 2ac\]


\[\Large SA-2ac = b(2a + 2c)\]


\[\Large b(2a + 2c) = SA-2ac\]


\[\Large b = \frac{SA-2ac}{2a + 2c}\]

Answer 13

that doesnt match any of my answer choices?

Answer 14

What are your answer choices

Answer 15

a.)SA/2(a+c)
b.)SA-4a/c
c.)1/2 Sa-ac/a+c
d.) 1/2SA/a+b+c

Answer 16

oh, for some reason, they're factoring out 2's (not sure why)



\[\Large b = \frac{SA-2ac}{2a + 2c}\]


\[\Large b = \frac{2(\frac{1}{2}SA-ac)}{2(a + c)}\]


\[\Large b = \frac{\frac{1}{2}SA-ac}{a + c}\]

Answer 17

thank you!

Answer 18

@BlahblerBlah, SA stands for the surface area of the prism