Question

Need some serious help in solving literal equations
I'm pretty ok when it comes to solving inequalities but now I have so many variables I'm not sure what to do...how do I solve for this stuff?
Solve for c.
ab + c = 5

Answer 1

You can't solve that without another equation...

Answer 2

what do you mean? why would you need another equation?

Answer 3

ok - first step here would be to subtract ab from both sides - what do you end up with?

Answer 4

c - 5 - ab?

Answer 5

no I meant c = 5 - ab

Answer 6

what happened to the equals sign?

Answer 7

yes :)

Answer 8

and there you have magically solved for c :)

Answer 9

I dont see how I can figure out what to do to solve for them. :/

Answer 10

you just need to keep an eye out for which variable you are solving for. then treat everything else as just "bundles" of unknown quantities

Answer 11

e.g. try solving this one for c:

xyz + 2c = c - pq

Answer 12

remember the main aim is to get the symbol of interest (c in this case) over to the left-hand-side, and everything else over to the right-hand-side

Answer 13

so I have to have the variable I'm solving for on the left side?

Answer 14

yes :)

Answer 15

it is always best to do these one step at a time

Answer 16

so first what do you think you would need to do in order to move the xyz to the right-hand-side?

Answer 17

there are two c's. Do I have to combine like terms, or do I have to keep it that way because both cs are on different sides of the equal sign?

Answer 18

just do one step at a time - so do the first step I asked above

Answer 19

do I subtract xyz from both sides?

Answer 20

perfect! - and what do you end up with?

Answer 21

making it 2c = c - pq - xyz

Answer 22

great! now next step would be to get that lone c from the right-hand-side over to the left

Answer 23

mm...I'm stuck...should I divide 2c and c by something?

Answer 24

think about what you need to do in order to remove the lone c from the right-hand-side, then apply that same process to the left

Answer 25

I would subtract c, but if I did thta, it would remove c entirely from the equation, wouldn't it?

Answer 26

that is correct - so subtract c from both sides - what do you end up with?

Answer 27

...2 = pq?

Answer 28

what happened there?

Answer 29

we started with:

2c = c - pq - xyz

we now need to subtract c from both sides

Answer 30

2c = pq - xyz, right?

Answer 31

remember that 2c - c = c

Answer 32

why is that? if I subtracted c from 2c that would make it 2, right?

Answer 33

2c = c - pq - xyz
-c = -c - pq - xyz
============
c = -pq - xyz

Answer 34

think of it like this: what is 2 apples take away one apple?

Answer 35

oh! I see! there are two cs and I am subtracting a c. I forgot that a variable counts as one digit

Answer 36

good - I hope it is becoming clearer for you now :)

Answer 37

yes, thank you. :]

Answer 38

yw :)