Question

[nguyenthichiem]

tính bằng cách hợp lí ;  ( 27 x 700 -  45 x 20) : ( 45 - 40 + 35 - 30 + 25 - 20 + 15 - 10 +5)

Answer 1

[Lê Minh Vũ]

\(\left(27.700-45.20\right)\div\left(45-40+35-30+25-20+15-10+5\right)\)

\(=\)\(\left(27.100-45.20\right)\div25\)

\(=\)\(\left(27.35.20-45.20\right)\div25\)

\(=\)\(\left[\left(27.35-45\right).20\right]\div25\)

\(=\)\(18000\div25\)

\(=\)\(750\)