Simplify the rational expression and then add or subtract. Express answers in simplest form and identify all non-permissible values.

Question

(The non-permissible value is not the issue. It is the simplification)

3x + 15/x^2-25 + 4x^2 -1/ 2x^2 + 9x -5

3(x+5)/(x+5)(x-5) + 4x^2 -1/ (x+5)(2x-1)

LCD: (x-5)(x+5)(2x-1)

6x^2+27x-15/(x+5)(x-5)(2x-1) + 2x^2 - 9x -5

8x^2 + 18x - 20/(x-5)(x+5)

2(4x^2+9x-10)/(x+5)(x-5)

(I know this isn't the right answer. Please help me :( )

Answer 1

one way to find your errors is this. Check each line with the same value of x, lets do it with x=0

3x + 15/x^2-25 + 4x^2 -1/ 2x^2 + 9x -5 VALUE: 15/-25 +1/5= -2/5

3(x+5)/(x+5)(x-5) + 4x^2 -1/ (x+5)(2x-1)
Value: 15/-25 + 1/5: -2/5


6x^2+27x-15/(x+5)(x-5)(2x-1) + 2x^2 - 9x -5
Value: -15/-25 + -5 SO THIS LINE IS WRONG RECHECK IT, and relook at the last term.

8x^2 + 18x - 20/(x-5)(x+5)

2(4x^2+9x-10)/(x+5)(x-5)

Answer 2

Thanks :D