Consider the following functions. Perform the operations to determine the values of a, b, c, d, and e. part a: f(x)=(x^2+7x-12) and g(x)=(x^2-9x+1) f(x)•g(x)=ax^4-bx^3-cx^2+dx-e part b: h(x)=(x^2+2) and k(x)=(2x^2-5x+7) h(x)•k(x)=ax^4-bx^3-cx^2+dx-e