Question

tính:

a, ( 3/4 -5/6 + 7/12) x (-12/7)

b, 1,4 x 15/49 - (4/5 + 2/3) :11/5

 

Answer 1

a)(3/4-5/6+7/12).(-12/7)=1/2.(-12/7)

=6/7

b)1,4.15/49-(4/5+2/3):11/5=1,4.15/49-22/15:11/5

=3/7-2/3=-5/21

Answer 2

(3/4-5/6+7/12)×(-12/7)

=(9/12-10/12+7/12)×(-12/7)

=(-1/12+7/12)×(-12/7)

=6/12×(-12/7)

=1/2×(-12/7)

=-12/14

=-6/7