Question

Tính nhanh

a) 24.(16-5)+16.(24-5)

b) 31.(-18)+31.(-81)-31

c) 13.(23+22)-3.(17+28)

Answer 1

Tải PHOTOMATH bạn nhé

Answer 2

a) 24.(16-5)+16.(24-5)

=24.16-24.5+16.24-16.5

=32.24-40.5

=...................

Answer 3

31.(-81)+31.(-81)-31

=31[(-81)-81-1]

=31.(-163)

=...........................

Answer 4

13(23+22)-3(17+28)

=13.23+13.22-3.17-3.18

=...................................

Answer 5

a) \(24.\left(16-5\right)+16.\left(24-5\right)\)

\(=24.16-24.5+16.24-16.5\)

\(=24\left(16+16\right)+5\left(-24-16\right)\)

\(=24.32+5.\left(-40\right)\)

\(=768+\left(-200\right)\)

\(=568\)

b) \(31.\left(-18\right)+31.\left(-81\right)-31\)

\(=31.\left[\left(-18\right)+\left(-81\right)-1\right]\)

\(=31.\left(-100\right)\)

\(=-3100\)

c) \(13.\left(23+22\right)-3.\left(17+28\right)\)

\(=13.45-3.45\)

\(=45.\left(13-3\right)\)

\(=45.10\)

\(=450\)