1. Tính nhanh:
a) \(125.\left(-24\right)+24.225\)
= \(-125.24+24.225\)
\(=24\left(-125+225\right)\)
\(=24\) . \(100\)
= \(2400\)
b) \(26.\left(-125\right)-125.\left(-36\right)+125.\left(-7\right)\)
\(=-26.125-125.\left(-36\right)+125.\left(-7\right)\)
\(=125\left[-26-\left(-36\right)+\left(-7\right)\right]\)
\(=125.3\)
\(=375.\)
a, \(125\cdot\left(-24\right)+24\cdot225\)
\(=\left(-125\right)\cdot24+24\cdot225\)
\(=24\cdot\left[\left(-125\right)+225\right]\)
\(=24\cdot100\)
\(=2400\)
b, \(26\cdot\left(-125\right)-125\cdot\left(-36\right)+125\cdot\left(-7\right)\)
\(=\left(-26\right)\cdot125-125\cdot\left(-36\right)+125\cdot\left(-7\right)\)
\(=125\cdot\left[\left(-26\right)+36-7\right]\)
\(=125\cdot3\)
\(=375\)