There is no need to enclose exponents in parentheses. Write "x^2" instead of "x^(2)".
And there certainly is no need to enclose the constant term in a polynomial in parentheses. Write "x+3" instead of "x+(3)". BUT there IS a need to enclose polynomials in parentheses when they are the numerator or denominator of a fraction.
And you have a fraction with polynomials divided by another fraction with polynomials, so you will need parentheses around each of those fractions.
The expression should look like this:
((x^2-3x-10)/(x+3))/((2x^2-7x-15)/(x^2-9))
The rule for dividing fractions is flip the second fraction (find its reciprocal) and multiply:
Now factor all the polynomials and cancel common factors where possible. I'll get you started....
