I have forgotten my algebra - please help...?

Question

I am an aging college student and it has been a long time since I took algebra. Can someone help me with this one (and please tell me how you get the answer)? Thanks!
[-15,984 (R-1) + -3996 (R)] / Rsquared - R = [-1.998 (Rsq - R)] / Rsq - R

Answer 1

To solve for R, you need to get all of your R terms on one side, and get the other terms on the other side.

The denominators are the same, so we don't care about them (making sure that R/=0 or 1, else the problem is undefined.)

-15984R+15984-3996R=-1998R^2+1998R
1998R^2-(15984+3996+1998)R+15984=0

Use the quadratic equation (R=(-b+/-sqrt(b^2-4ac))/2a, where a is in front of R^2, b in front of R, and c your constant, to solve for two possible values of R.

Answer 2

Hi,

following on from your third answerer i get.

1998R^2-21988R+ 15984 = 0
Using the equation he gave you get.

R = -(-21988) +/- Sqrt( (-21988)^2 - 4(1998)(15984) )
_________________________________________
2(1998)
= 21988 +/- 18860.75333
____________________
3996

R has 2 solutions.
= (21988 + 18860.75333)/3996
and (21988 - 18860.7533)/3996
which gives

R = 10.22241074 and R = 0.782594261
Which are the solutions of the given equation

You can prove these are the solutions by putting them into the original equation or the simplified equation.

15984(10.22241074)^2 - 21988(10.22241074) +15984
= 0 ( it equals zero so this values is the solution to the equation)
And similarly you can show that R= 0.782594261 is also a solution.

Choose how many decimal places you need 1 or 2 usually.
Hope this helps.

:-)

Answer 3

Assuming I'm reading this right (I'm not sure about some of the ( ):
multiply all terms by R^2 & distribute terms:
-15984R+15984-3996R-R^3=-1.998R^2+1.998R-R^3
add R^3 to each side & rearange:
1.9898R^2-19978.002R+15984=0
Use the quadratic formula:

R1=(19978.002+sqrt(19978.002^2-4*1.998*15984))/(2*1.998)

R2=(19987.002-sqrt(19978.002^2-4*1.998*15984))/(2*1.998)

Answer 4

After you multiply both sides of the equation by r*-r you have an equation that can be solved using the formula for a quadrtic equation. This formula is x =(-b(+/-SQR9(b*-4ac)/2.

See: http://mathworld.wolfram.com/QuadraticEquation.html

Answer 5

Hun,then you should know that asking for easy answers isn't the thing to do

Answer 6

use this sight it is a good one http://www.gomath.com/

Answer 7

MyDearAuntSally.................(multiply, division, addition, and subtraction)

Answer 8

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