I managed to do qn 8, need help with qn 7 and 9

i) Is 0. Because after integrating, if you substitute 3 as both the upper and lower limit, and subtract them from one another, the value is 0.

ii) Is 5(-2). Because you can 'bring' 5 out of the integral leaving the expression given, then multiply it by 5.

iii)Is the same as ii), as 5pi/2 is a constant. However, the integral is now the negative of what is given because the limits have been swapped.