(6) (4 marks) In questions 6a-6b, evaluate the given integral using properties of definite integrals and substitution. 3 (a) Let f(x)dx = 3 and 2f(x) dx = 4 and 3f(x)dx = -3. Find fo f(x) dx. o (b) Let xh(x') dx = 3. Find ffh(x) dx