5. x <= 2
6. x > -6
7. w>1
8. m>-4
9. x <= 2 or x>= 8
10. no solution
11. n>= -1 or n <-5
12. k= 15/2 and k>= 4
to solve for y, we must multiply by t on both side to get ride of the t in the denominator. By doing this, we will get:

on the right side.
Subtracting 3, and we have successfully isolated y.
It would be impossible to get a quantitative value for y if we don't know the value of t.
[ ( x + 4 )( x + 5 ) + 4( x + 1 )( x + 5) - 5( x + 1 )( x + 4 ) ] / [( x + 1 )( x + 4)( x + 5 )] = ( x^2 + 9x + 20 + 4x^2 + 24x +20 - 5x^2 - 25x - 20) / [( x + 1 )( x + 4)( x + 5 )] =
( - 2x + 20 ) / [( x + 1 )( x + 4)( x + 5 )] = ( - 2)( x - 10) / [( x + 1 )( x + 4)( x + 5 )]