Question

Tính bằng cách thuận tiện nhất:
a/ 17,5 x 4 x 3 x 25               d/ 7,7 x 9 + 7,7
c/ 4,52 x 12,5 – 2,5 x 4,25      b/ 25,6 x 7,5 + 25,6 x 2,5

Answer 1

a: \(17,5\cdot4\cdot3\cdot25\)

\(=17,5\cdot3\cdot\left(4\cdot25\right)\)

\(=52,5\cdot100=5250\)

b: \(25,6\cdot7,5+25,6\cdot2,5\)

\(=25,6\left(7,5+2,5\right)\)

\(=25,6\cdot10=256\)

c: \(4,52\cdot12,5-2,5\cdot4,25\)

\(=2,5\left(4,52\cdot5-4,25\right)\)

\(=2,5\cdot18,35=45,875\)

d: \(7,7\cdot9+7,7\)

\(=7,7\left(9+1\right)\)

\(=7,7\cdot10=77\)