Here, I'll make your life a little bit easier:
We have: \((2x+10)(x+3)<(3x+9)(x-8)\)
Now, factor \(3x + 9\): \((2x + 10)( x+3) < 3(x + 3)(x-8)\)
Note that because both sides have an \(x + 3\), we can cancel them, giving us \(2x + 10 < 3(x-8)\).
To finish, solve it like you would a regular equation, but make sure the sign( < or >) satisfies the equation.