Bài 1: Áp dụng tính chất các phép tính để tính nhanh:
a) \(\left(-2,5\cdot0,38\cdot0,4\right)-\left[0,125\cdot3,15\cdot\left(-8\right)\right]\)
b) \(\left[\left(-20,83\right)\cdot0,2+\left(-9,17\right)\cdot0,2\right]:\left[2,47\cdot0,5-\left(-3,53\right)\cdot0,5\right]\)
a/ \(\left(-2,5.0,38.0,4\right)-\left[0,125.3,15.\left(-8\right)\right]\)
\(=\left(-0,95.0,4\right)-\left[0,39375.\left(-8\right)\right]\)
\(=-0,38-3,15=2,77\)
b/ \(\left[\left(-20,83\right).0,2+\left(-9,17\right).0,2\right]:\left[2,47.0,5-\left(-3,53\right).0,5\right]\)
\(=\left[-4,166+-1,834\right]:\left[1,235--1,765\right]\)
\(=-6:3\)
\(=-2\)