# Thread: solve for c (have fun!)

1. ## solve for c (have fun!)

not sure how to do this myself, but I need someone to solve this expression for c. Please include the steps in your response.

$\displaystyle a(1-c) + 1.018(c) = b$

enjoy!

2. Originally Posted by anasteso1454
not sure how to do this myself, but I need someone to solve this expression for c. Please include the steps in your response.

$\displaystyle a(1-c) + 1.018(c) = b$

enjoy!
$\displaystyle a-ac+1.018c = b$

$\displaystyle c(a+1.018) = b-a$

3. a1-ac+1.018c = b

c = (b-a1)/(1.018-a)

4. Originally Posted by anasteso1454
not sure how to do this myself, but I need someone to solve this expression for c. Please include the steps in your response.

$\displaystyle a(1-c) + 1.018(c) = b$

enjoy!
I agree with Monocerotis.

Expand & remove parenthethics:
a - ac + 1.018c = b

slight rearrangement:
a + 1.018c - ac = b

subtract a from both sides & reduce
1.018c - ac = b - a

isolate c
c(1.018-a) = b - a

divide thorough by parenthetic
c = $\displaystyle \dfrac{ b - a}{ (1.018 - a ) }$

.

5. thanks so much, guys!

you have just helped to develop an equation to predict salinity change in a marine aquarium!

(I got stuck in figuring out how to solve it...)