SOLUTION: I'm stuck on a couple of questions. 1.) I = E/R + r Solve for r I can't seem to comprehend the formula to use to solve. 2.) 3/2y - 3/2y+4 Reduce the answer to lowest

Algebra ->  Rational-functions -> SOLUTION: I'm stuck on a couple of questions. 1.) I = E/R + r Solve for r I can't seem to comprehend the formula to use to solve. 2.) 3/2y - 3/2y+4 Reduce the answer to lowest       Log On


   

Question 52837: I'm stuck on a couple of questions.
1.) I = E/R + r Solve for r
I can't seem to comprehend the formula to use to solve.
2.) 3/2y - 3/2y+4 Reduce the answer to lowest terms.
3.) X^-3 = 8 Solve the equation.
Any help and guidance of the formulas and steps involved would be appreciated.
Found 2 solutions by Earlsdon, funmath:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
1) Solve for r:
I+=+E%2FR+%2B+r Subtract E%2FR from both sides of the equation.
I-%28E%2FR%29+=+r or r+=+I-%28E%2FR%29 This could also be written:
I+=+%28IR-E%29%2FR
2) Reduce to lowest terms:
3%2F2y+-+3%2F%282y%2B4%29 A common denominator is 2y%282y%2B4%29
%283%282y%2B4%29-3%282y%29%29%2F%282y%282y%2B4%29%29 Simplifying this.
%286y%2B12-6y%29%2F%284y%5E2%2B8y%29 Simplifying further.
12%2F4%28y%5E2%2B2y%29 Cancel the 4's
3%2F%28y%5E2%2B2y%29 or 3%2Fy%28y%2B2%29
3)Solve:
x%5E%28-3%29+=+8 Rewrite as:
1%2Fx%5E3+=+8 Multiply both sides by x%5E3
1+=+8x%5E3 Divide both sides by 8.
1%2F8+=+x%5E3 Take the cube root of both sides.
1%2F2+=+x or x+=+1%2F2

Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
1.) I=E/R+r
I-E/R=-E/R+E/R+r
I-E/R=r
2.) 3/2y-3/2y+4
(3/2-3/2)y+4
0+4
4
3.) I'm going to show you this two ways because I don't know what level of math you're taking. Do whatever makes sense to you.
x^-3=8
1/(x^3)=8
(x^3)(1/(x^3))=(8)(x^3)
1=8x^3
1/8=8x^3/8
1/8=x^3
3root(1/8)=3root(x^3)
1/2=x
________________________________
x%5E-3=8
%28x%5E-3%29%5E%28-1%2F3%29=%288%29%5E%28-1%2F3%29
%28x%5E-3%29%5E%28-1%2F3%29=%282%5E3%29%5E%28-1%2F3%29
x%5E%28%28-3%2F1%29%2A%28-1%2F3%29%29=2%5E%28%283%2F1%29%2A%28-1%2F3%29%29
x%5E%283%2F3%29=2%5E%28-3%2F3%29
x=2%5E-1
x=1%2F2