Question

tính bằng cách thuận tiện

35 x 42 / 5 x 2

54 x 35 / 7 x 9

Answer 1

a ) \(=\frac{35\cdot42}{5\cdot2}=\frac{7\cdot5\cdot2\cdot21}{5\cdot2}\)

\(=\frac{7\cdot21}{1}=147\)

b) \(=\frac{54\cdot35}{7\cdot9}\)

\(=\frac{6\cdot9\cdot7\cdot5}{7\cdot9}\)

\(=\frac{6\cdot5}{1}=30\)

Answer 2

35x42/5x2= 5x7x2x12/5x2=84

54x35/7x9=6x9x7x5/7x9=30