Question

      Tinh nhanh :

a,2019 +2019 x99            b,7/3 x 5/9+5 x3/7       c,2018x7+2018+2018x2       d,225x63/9x15

Answer 1

mk ko viết đề ra nhé

a,2019 x (1 + 99)

=2019 x 100

=201900

c,2018 x (7 + 1 + 2)

=2018 x 10

=20180

mk chỉ bk phần a và c thôi hihi

Answer 2

a) \(2019+2019\times99=2019\times\left(1+99\right)=2019\times100=201900\)

b) \(\frac{7}{3}\times\frac{5}{9}+5\times\frac{3}{7}=\frac{35}{27}+\frac{15}{7}=\frac{650}{189}\)

c) \(2018\times7+2018+2018\times2=2018\times\left(7+1+2\right)=2018\times10=20180\)

d) \(\frac{225\times63}{9\times15}=\frac{15\times15\times9\times7}{9\times15}=15\times7=105\)