Question 584770
You just take each number in the first parenthesis and times them by the numbers in the second set. 

6x^3-9x^2         <------ 3x^2 times second set.

    -4x^2+6x      <------ -2x times the second set.

          10x-15  <------ 5 times the second set.
________________ +        Add them all up.
6x^3-13^2+16x-15  
________________

Hope this helped,
Alex Vandermeulen, Junior in High School.