Question

tính nhanh:

5x6x7x9/12x7x27=...............

4x5x6/12x10x8+1=...............

 

Answer 1

5*6*7*9/12*7*27

=5*6*7*3*2/2*6*7*3*3

=5*1*1*1*1/1*1*1*1*3

=5/3

Answer 2

5x6x7x9 / 12x7x27 = 5x6x7x9 / 2x6x7x3x9 = 5 / 2x3 = 5 / 6

4x5x6 / 12x10x8+1 = 4x5x6 / 2x6x2x5x2x4+1 = 1 / 2x2x2+1 = 1 / 8+1 = 1 / 9

Answer 3

a,5/6

b,120/961