Câu 3: Tìm x
a) `40% – x = – 2 2/5`
b) `(x/-5 + 2/3) : 2 1/5 – 1,4 . 15/49 = |-5|/21`
Câu 3: Tìm x a) `40% – x = – 2 2/5` b) `(x/-5 + 2/3) : 2 1/5 – 1,4 . 15/49 = |-5|/21`
By Melanie
By Melanie
Câu 3: Tìm x
a) `40% – x = – 2 2/5`
b) `(x/-5 + 2/3) : 2 1/5 – 1,4 . 15/49 = |-5|/21`
a)` 40% – x = -2 2/5`
`2/5 – x= -12/5`
`x = 2/5 + 12/5`
`x=14/5`
b) `(x/(-5) +2/3) : 2 1/5 – 1,4. 15/49 = (|-5|)/21`
`(-x/5 + 2/3) : 11/5 – 3/7 = 5/21`
`(-x/5 + 2/3) : 11/5 = 2/3`
`-x/5 + 2/3 = 22/15`
`-x/5 = 4/5`
`x=-4`
Câu 3:
a. 40% – x = -2$\frac{2}{5}$
$\frac{2}{5}$ – x = -2$\frac{2}{5}$
x = $\frac{2}{5}$ – (-2$\frac{2}{5}$)
x = $\frac{2}{5}$ + 2$\frac{2}{5}$
x = 2$\frac{4}{5}$
b. ($\frac{x}{-5}$ + $\frac{2}{3}$) : 2$\frac{1}{5}$ – 1,4.$\frac{15}{49}$ = $\frac{|-5|}{21}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ – $\frac{7}{5}$ .$\frac{15}{49}$ = $\frac{5}{21}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ – $\frac{1}{1}$ .$\frac{3}{7}$ = $\frac{5}{21}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ – $\frac{3}{7}$ = $\frac{5}{21}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ = $\frac{5}{21}$ + $\frac{3}{7}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ = $\frac{5}{21}$ + $\frac{9}{21}$
($\frac{x}{-5}$ + $\frac{2}{3}$) : $\frac{11}{5}$ = $\frac{2}{3}$
$\frac{x}{-5}$ + $\frac{2}{3}$ = $\frac{2}{3}$.$\frac{11}{5}$
$\frac{x}{-5}$ + $\frac{2}{3}$ = $\frac{22}{15}$
$\frac{x}{-5}$ = $\frac{22}{15}$ – $\frac{2}{3}$
$\frac{x}{-5}$ = $\frac{22}{15}$ – $\frac{10}{15}$
$\frac{x}{-5}$ = $\frac{12}{15}$
$\frac{x}{-5}$ = $\frac{4}{5}$
$\frac{x}{-5}$ = $\frac{-4}{-5}$
x = -4