Thực hiện phép tính:
a, $\frac{2}{3}$ $-$ $\frac{5}{7}$ $×$ $\frac{14}{25}$
b, $\frac{-2}{5}$ $×$ $\frac{5}{8}$ $+$ $\frac{5}{8}$ $×$ $\frac{3}{5}$
c, $\text{25%}$ $-$ $\text{1}$$\frac{1}{2}$ $+$ $\text{0,5}$ $×$ $\frac{12}{5}$
Thực hiện phép tính:
a, $\frac{2}{3}$ $-$ $\frac{5}{7}$ $×$ $\frac{14}{25}$
b, $\frac{-2}{5}$ $×$ $\frac{5}{8}$ $+$ $\frac{5}{8}$ $×$ $\frac{3}{5}$
c, $\text{25%}$ $-$ $\text{1}$$\frac{1}{2}$ $+$ $\text{0,5}$ $×$ $\frac{12}{5}$
Đáp án:
tham khảo ạ≈ω
Giải thích các bước giải:
` 2/3 – 5/7 . 14/25 `
`= 2/3 – 2/5 `
`=4/15 `
` -2/5 × 5/8 + 5/8 × 3/5 `
`= 5/8 × ( -2/5 + 3/5 )`
`=5/8×1/5 `
`=1/8 `
` 25% – 1 1/2 + 0,5 × 12/5 `
`= 1/4 – 3/2 + 1/2 × 12/5 `
`= 1/4 – 3/2 + 6/5 `
`=-5/4 + 6/5 `
`=-1/20`
Đáp án:
a) 2/3 – 5/7 . 14/25
= 2/3 – 2/5
= 10/15 – 6/15 = 4/15
b) -2/5 . 5/8 + 5/8 . 3/5
= (-2/5 + 3/5) . 5/8
= 1/5 . 5/8 = 1/8
c) 25% – 1 1/2 + 0,5 . 12/5
= 1/4 – 3/2 + 1/2 . 12/5
= -5/4 + 6/5
= -25/20 + 24/20 = -1/20
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