Question

Bài: tính nhanh

B=4/9*(-1/19)+5/9*(-1/19)

Answer 1

B=(\(\left(\dfrac{4}{9}+\dfrac{5}{9}\right).\left(\dfrac{-1}{19}\right)\)

   =1.\(\dfrac{-1}{19}\)

   =\(\dfrac{-1}{19}\)

Answer 2

=(-1/19)x(4/9+5/9)

=(-1/19)x(9/9)

=(-1/19)x1

=-1/19

Answer 3