C czagara Junior Member Joined Sep 24, 2009 Messages 67 Sep 24, 2009 #1 (2X+5) / (X+1) - (3X) / (X^2 + X) = 2 Here is what I came up with so far: LCD: X(X+1) 2X^2 + 5x - 3x =2X^2 + 2x 2X^2 + 2X = 2X^2 + 2x Is that right? My book says the answer is all real numbers except 0, and -1
(2X+5) / (X+1) - (3X) / (X^2 + X) = 2 Here is what I came up with so far: LCD: X(X+1) 2X^2 + 5x - 3x =2X^2 + 2x 2X^2 + 2X = 2X^2 + 2x Is that right? My book says the answer is all real numbers except 0, and -1
mmm4444bot Super Moderator Joined Oct 6, 2005 Messages 10,825 Sep 24, 2009 #2 czagara said: … 2X^2 + 2X = 2X^2 + 2x Is that right? … It's good, so far. Click to expand... Did you notice that the expressions are identical on each side of the equal sign, in your last result? So, any Real number for x will satisfy this equation. We need to remember that the factors x and x + 1 appear in denominators in the original equation. So, any value of x that causes a denominator to evaluate to zero must be excluded from the solution set. This is why the solution set is all Real numbers except x = 0 and x = -1.
czagara said: … 2X^2 + 2X = 2X^2 + 2x Is that right? … It's good, so far. Click to expand... Did you notice that the expressions are identical on each side of the equal sign, in your last result? So, any Real number for x will satisfy this equation. We need to remember that the factors x and x + 1 appear in denominators in the original equation. So, any value of x that causes a denominator to evaluate to zero must be excluded from the solution set. This is why the solution set is all Real numbers except x = 0 and x = -1.