Algebra Formula question?

Question

R=r+400(w-l)/n

I cant understand why I keep gettin lost on this formula. Is there anywhere I can read more information on the logic of solving a problem like this, my textbook don't seem clear to me.

Just started college after 18 years away from doing any math like this and what use to be my favorite subject is now becoming one of my most difficult

Solve for l


sorry, thats one of my problems, missing things. the cobwebs in my brain are slowly clearing though.

Answer 1

What are you trying to solve for? Try looking up 'College Algebra" on google or yahoo. You should also try http://www.sparknotes.com/math which is another useful resource (but beware, there are errors in their tutorials)


Solve for L: R=r+400(w-l)/n

I am guessing that the function is written as..(the 'r' term is not over the n)

R=r+(400(w-l)/n)

so i am going to minus r from both sides

R - r = (400(w-l)/n)

NOw i am going to multply 'n' to both sides, so i get rid of the divided by n on the right side.

n(R-r) = 400(w-l) * n
----------------
.....................n

n's cross out.. i have

n(R-r) = 400(w-l)

Now im going to divide by 400, because its attached to (w-l)

n(R-r)/400 = 400(w-l)/400

n(R-r)/400 = (w-l)

add l to both sides


n(R-r)/400 + l = w

Answer 2

To solve for "l" isolate it by transposing all other terms to one side of the equation, so that you get

l = W - (nR - r)/400

How? Transpose other terms on the side of your unknown to the other side of the equation. This is best done one by one.

Transposing is easy; just remember that with an equation, you can do anything on one side of the equals sign, as long as you do likewise to the other side to maintain the equation.

It is helpful to recall:
- a term divided by itself equals 1;
- a term multiplied by 1 is still that term;
- a term minus itseld equals 0.

With your original equation:
Step 1. Transpose n: multiply both sides by "n" so that you get
nR = n (r + 400 (W - l)) / n but since n/n = 1, then
nR = r + 400 (W - l).

Step 2. Transpose "r" by subtracting "r" from both sides, so that
nR - r = r + (400) (W-l) -r but since r - r = 0, then
nR - r = 400 (W - l).

Step 3. Transpose "400" by dividing both sides by 400 so that
(nR - r) / 400 = 400 (W - l) / 400 but since 400 / 400 = 1, then
(nR - r) / 400 = W - l.

Step 4. Transpose "W": subtract W from both sides, so that

(nR - r) / 400 - W = W - l - W but since W - W = 0, then
(nR - r) / 400 - W = - l.

Step 5. To remove the negative sign of "l" multiply both sides by -1 (negative multiplied by negative equals positive):

-1 ((nR - r)/400 - W) = -1 (-l)
- (nR - r) / 400 + W = + l or rearranging:

W - (nR - r) / 400 = l or

l = W - (nR - r) / 400

Tadaaah!

For the other variables, use the same method and you get

W = l + (nR-r) / 400

r = nR - 400 (W - l)

n = (r + 400 (W - l) / R

Answer 3

I can see why you keep getting lost on this problem when there isn't even a problem to begin with. I don't recall ever seeing that equation in a math class before. Looks more like an applications course such as engineering or physics.

Answer 4

One equation and 5 unknowns? Not bloody likely. You need much more information.

Answer 5

R=r+400(w-I)/n
R=r+400w-400l/n
R=r+400w-400l/n R=r+w-l/n
l=r+w/n-R

Answer 6

order of operations i suppose
parenthesis
exponents
multiplication/ division (whichever comes first)
addition/ subtraction (whichever comes first)

first do (w-l)
then multiply whatever you got by 400
divide that number by n
then add r



edit: i think its -400/n-w=l

Answer 7

You never told us what you're solving for...