bài 1:Thực hiện phép tính
$\frac{2}{5}$ + ($\frac{-4}{5}$) + ($\frac{-1}{2}$)
bài 2: Tìm x
a)x+ $\frac{1}{3}$ = $\frac{2}{5}$ – $\frac{-1}{3}$
b)$\frac{7}{4}$ – (x+ $\frac{5}{3}$) = $\frac{-12}{5}$
c) x – [$\frac{17}{2}$ – ($\frac{-3}{7}$ + $\frac{5}{3}$) = $\frac{-1}{3}$
d)
Đáp án:
Bài `1 :`
`2/5 + ((-4)/5) + ((-1)/2)`
`=((-2)/5) + ((-1)/2)`
`= (-9)/10`
Bài `2 :`
`a, `
` x + 1/3 = 2/5 – (-1)/3`
` x + 1/3 = (11)/15`
`x = (11)/15 – 1/3 = 2/5`
`b, `
`7/4 – ( x + 5/3 ) = (-12)/5`
` x + 5/3 = (83)/20`
`x = (149)/60`
`c,`
`x – [ (17)/2 – ((-3)/7 + 5/3 ) = (-1)/3`
`x – ( (17/2 – (26)/21 ) = (-1)/3 `
`x – (305)/42 = (-1)/3 `
`x = (97)/14`
Good luck !
Đáp án:
Bài 1:
$\frac{2}{5}$ + ($\frac{-4}{5}$) + ($\frac{-1}{2}$)
= ($\frac{-2}{5}$) + ($\frac{-1}{2}$)
= ($\frac{-4}{10}$) + ($\frac{-5}{10}$)
= $\frac{-9}{10}$
Bài 2:
a) x + $\frac{1}{3}$ = $\frac{2}{5}$ – $\frac{-1}{3}$
x + $\frac{1}{3}$ = $\frac{2}{5}$ + $\frac{1}{3}$
x + $\frac{1}{3}$ = $\frac{11}{15}$
x = $\frac{11}{15}$ – $\frac{1}{3}$
x = $\frac{2}{5}$
Vậy x = $\frac{2}{5}$
b) $\frac{7}{4}$ – (x + $\frac{5}{3}$) = $\frac{-12}{5}$
x + $\frac{5}{3}$ = $\frac{7}{4}$ – $\frac{-12}{5}$
x + $\frac{5}{3}$ = $\frac{7}{4}$ + $\frac{12}{5}$
x + $\frac{5}{3}$ = $\frac{83}{20}$
x = $\frac{83}{20}$ – $\frac{5}{3}$
x = $\frac{149}{60}$
Vậy x = $\frac{149}{60}$
c) x – [$\frac{17}{2}$ – ($\frac{-3}{7}$ + $\frac{5}{3}$)] = $\frac{-1}{3}$
x – [$\frac{17}{2}$ – $\frac{26}{21}$] = $\frac{-1}{3}$
x – [$\frac{17}{2}$ + $\frac{-26}{21}$] = $\frac{-1}{3}$
x – $\frac{305}{42}$ = $\frac{-1}{3}$
x = $\frac{-1}{3}$ + $\frac{305}{42}$
x = $\frac{97}{14}$
Vậy x = $\frac{97}{14}$
d) Thiếu dữ liệu