http://oi58.tinypic.com/s1j8yu.jpg
considerando 5*f (x ) = 7x^2 + 4, temos f (x ) = (7x^2 +
4)/5 => int[(7x^2 + 4)/5]=> int[(7x^2 + 4)]/5 = (1/5)*[int(7x^2) + int(4)] => (1/5)*[(7/3)x^3 + (4/2)x^2]
Colocando em evidência, temos: (1/5)*x^2[(7/3)x + (4/2)]