Question

Tính bằng hai cách:

a) 93 x 8 + 93 x 2

b) 36 x 9 + 64 x 9

c) 57 x 8 – 57 x 7

Answer 1

\(a,C1=744+186\\ =930\\ C2=93\times\left(8+2\right)\\ =93\times10=930\\ b,C1:=324+576\\ =900\\ C2=9\times\left(36+64\right)\\ =9\times100\\ =900\\ c,C1=456-399\\ =57\\ C2=57\times\left(8-7\right)\\ =57\)

Answer 2

\(a)\)\(93\times8+93\times2\)

\(=98\times\left(8+2\right)\)

\(=98\times10\)

\(=980\)

 

\(b)36\times9+64\times9\)

\(=9\times\left(36+64\right)\)

\(=9\times100\)

\(=900\)

 

\(c)57\times8+57\times7\)

\(=57\times\left(8-7\right)\)

\(=57\times1\)

\(=57\)