Nếu 4 ∫ 1 f ( x ) d x = 3 thì 4 ∫ 1 [ 1 3 f ( x ) − 5 ] d x bằng
Giải thích
Chọn C
\(\int\limits_1^4 {\left[ {\frac{1}{3}f\left( x \right) - 5} \right]dx} \)\( = \frac{1}{3}\int\limits_1^4 {f\left( x \right)dx} - \left. {5x} \right|_1^4\)\( = \frac{1}{3}.3 - 15 = - 14\).