Question

tính nhanh

3,24×1,7+1,7×4,65-13,78×0,85

Answer 1

\(3,24\times1,7+1,7\times4,65-13,78\times0,85\)

\(=\)\(3,24\times1,7+1,7\times4,65-6,89\times2\times0,85\)

\(=\)\(1,7\times\left(3,24+4,65\right)-6,89\times2\times0,85\)

\(=\)\(1,7\times7,89-6,89\times1,7\)

\(=\)\(1,7\times\left(7,89-6,89\right)\)

\(=\)\(1,7\times1\)

\(=\)\(1,7\)

Answer 2

Cách 2:

\(3,24\times1,7+1,7\times4,65-13,78\times0,85\)

\(=\)\(3,24\times1,7+1,7\times4,65-6,89\times1,7\)

\(=\)\(1,7\times\left(3,24+4,65-6,89\right)\)

\(=\)\(1,7\times1\)

\(=\)\(1,7\)