Question

Bài 1: Thực hiện phép tính bằng cách hợp lí < nếu có thể >

a, \(\left(-1,5\right).\left(1+\frac{2}{3}\right)+1,4.\frac{15}{49}-\left(\frac{4}{5}+\frac{2}{3}\right):2\frac{1}{5}\)

b, \(\frac{7}{5}+\frac{4}{5}\left(\frac{5}{8}-\frac{7}{4}\right)+2014^0\)

c, \(1\frac{3}{25}+\frac{17}{19}-\frac{3}{25}+0,9+\frac{2}{19}\)

d, \(-\frac{5}{9}.\frac{6}{13}+\frac{-5}{9}.\frac{7}{23}+\frac{5}{23}:\frac{9}{7}\)

Bài 2: Tìm x, biết

a, 20%x + 0,4x = 4,5

b, \(\left(3\frac{1}{2}-2\left|x-1\right|\right).2\frac{2}{3}=5\frac{1}{3}\)

HELP MEEEEE

Answer 1

Bài 1:

d)

= \(\frac{-5}{9}\left(\frac{6}{13}+\frac{7}{13}\right)+\frac{5}{23}.\frac{7}{9}\)

= \(\frac{-5}{9}.1+\frac{35}{207}\)

= \(\frac{-80}{207}\)

Answer 2

Bài 2:

a) 20%x + 0,4x = 4,5

x( 20% + 0,4 ) = 4,5

x. 0,6 = 4,5

x = 4,5 : 0,6

x = 7,5