Question

Which equation is solved for the variable *c*.
a(b-c) =d
A.) c= ab-d/b
B.) c= ab+d/a
C.) c= d-ab/a
D.) c= ab-d/a
Reassurance help? XD

Answer 1

a(b-c) =d
ab - ac = d
ad - d = ac

now divide both sides by a

Answer 2

I'm not given any variables, I don't get it q.q

Answer 3

a(b-c) =d (divide a on both sides)
b-c = d/a (subtract b on both sides)
-c = (d/a) - b (reverse signs to get a positive c)
c = -(d/a) +b

a(b-c) =d (multiply a into parenthesis)
ab - ac = d (subtract ab on both sides)
-ac = d - ab (divide both sides by -a)
c = -(d/a) + b

Answer 4

sorry typo
last line should be
ab - d = ac

Answer 5

Doesn't seem to match any of the choices though, sure you entered them right?

Answer 6

So confused.

Answer 7

And yes, my lest question had a typo on the actual test apparently. So this could be incorrect, I'm not sure

Answer 8

Basically you're just trying to get C by itself by using algebra

Answer 9

But I don't know how to ._. That's what I've been trying to figure out

Answer 10

Alright...so you're starting with a(b-c) =d

Answer 11

looks like there's one a too many in option D

Answer 12

a(b-c) =d
To get the "a" to the other side, you divide by it on other sides
and you're left with (b-c) = d/a

Answer 13

So then I just keep doing that?

Answer 14

(b-c) = d/a
To get the "b" on the other side, just subtract it on both sides
and you're left with -c = (d/a) -b

Answer 15

This is so frustratingly confusing to me, I'm sorry. Bad at math in general

Answer 16

-c = (d/a) -b
Since you want "C" to be positive, you reserve the signs on both sides
and you get
c = -(d/a) + b

Answer 17

So, there's 2 sides to this equation
a(b-c) =d

a(b-c) on the left side
and
"d" on the right side

and you want to get c by itself

Answer 18

Step 1
- you want to get ride of the "a" on the left side
a(b-c)
-to do that, you want to divide the left side by "a"
-but by doing that, you also have to divide the right side by "a" (what you do to one side, you also have to do to the other side

So...you're left with
(b-c) on the left side
and
(d/a) on the right side

Answer 19

Oh, so then it's also like rewriting the equation each time till you get to the final "product"..?

Answer 20

yep

Answer 21

So then... (b-c) = (d/a)

Just wanna make sure I'm following correctly

Answer 22

Step 2 - so now you have

(b-c) on the left side

(d/a) on the right side

- Now you want to get ride of the "b" on the left side.
- To do that, you have to subtract "b" from the left side, which you also have to do to the right side

You can break the parenthesis on the left side
b - c - b = -c on the left side
and
(d/a) - b on the right side

Answer 23

and yes, that's correct

Answer 24

How do you get negative c? Ugh I don't understand at all.

Answer 25

Step 3

(-c) on left side by itself, but it's negative currently

((d/a) - b) on the right side

Since you want an equation to find the positive value of "c", you want to reverse the signs on both sides to give you

c (positive) on the left side
and
(-(d/a) + b) on the right side

put it all together

c = -(d/a) + b

Answer 26

I don't have an option with anything close to that. D;

Answer 27

During step 2, the "C" is already negative

(b-c)

the C is negative, while the B is positive (note the subtraction sign in front of C)

Answer 28

Oh..? So when you're taking away the b, you aren't taking the sign with it...??

Answer 29

Yeah, I looked through the answers and none of them seem to match the answer I got. Either I completely messed up, or there's a mistype

Answer 30

I'm thinking my whole quiz is messed up. I was asked to solve for "variable a" in a previous question and there was no a anywhere.

Answer 31

Nop, the negative sign (-) stays with the C
The B is positive
You're basically adding a negative B (-b) to both sides

Answer 32

Oh ok, makes a bit more sense now

Answer 33

C.) c= d-ab/a
seems closed to the answer
if only:
C.) c= (d-ab)/(-a)

Answer 34

I guess I'll go with that one lol. I'll tell you what it says afterwards if you'd like.

Answer 35

And thank you like so much for the help u-u I've been stumped on all these for days

Answer 36

actually...D could work also, but it needs a parenthesis

Answer 37

Oh, I'll just go with C.

Answer 38

D.) c= ab-d/a
to
c = (ab-d)/a

idk...D seems to be closer since it's only missing a parenthesis, while C is missing parenthesis and a negative sign

Answer 39

Well...either way, if it is a mistype, it's on whoever typed/wrote that test

Answer 40

Okay, I'll have to ask my teacher about it afterwards. This seems to happen a lot, actually.

Answer 41

Alright...good luck

Answer 42

D was correct. I also asked a friend about it and he said that parenthesis should've been included.

Answer 43

@porkbuns