Question 68307
Please help me solve for R for this equation:
{{{ (R/(R+1)) + 2=(3R)/(R+2)}}}
:
Get rid of the denominators, multiply each term by (R+1)(R+2), results:
:
R(R+2) + 2(R+1)(R+2) = 3R(R+1)
:
R^2 + 2R + 2(R^2 + 3R + 2) = 3R^2 + 3R
:
R^2 + 2R + 2R^2 + 6R + 4 = 3R^2 + 3R
:
Group like terms on the left, -4 all alone on the right:
:
R^2 + 2R^2 - 3R^2 + 2R + 6R - 3R = -4
:
The R^2's cancel out leaving us with:
5R = -4
R = -4/5
:
It easier to check the solution if R=-.8:
Substitute -.8 for R:
:
{{{ (R/(R+1)) + 2=(3R)/(R+2)}}}
:
{{{ (-.8/(-.8+1)) + 2=(3(-.8))/(-.8+2)}}}
:
{{{ (-.8/(.2)) + 2=(-2.4)/(1.2)}}}
:
- 4 + 2 = -2; checks our solution