Đáp án+Giải thích các bước giải:
b.
(1$\frac{2}{25}$ + $\frac{14}{9}$ + $\frac{17}{5}$ ) - ($\frac{2}{25}$ + $\frac{5}{9}$ + 40%)
= ($\frac{27}{25}$ +$\frac{14}{9}$+$\frac{17}{5}$ ) - ($\frac{2}{25}$ + $\frac{5}{9}$ + $\frac{2}{5}$)
= ($\frac{27}{25}$- $\frac{2}{25}$) + ( $\frac{14}{9}$-$\frac{5}{9}$) + ($\frac{17}{5}$ - $\frac{2}{5}$ )
= 1 + 1 + 3
= 5
c.
($\frac{2525}{2727}$ x $\frac{272727}{2929292}$) x $\frac{32}{y-2007}$ = 1$\frac{1}{7}$ x $\frac{50}{29}$
= ($\frac{25}{27}$ x $\frac{27}{29}$) x $\frac{32}{y-2007}$ = $\frac{8}{7}$ x $\frac{50}{29}$
$\frac{25}{29}$ x $\frac{32}{y-2007}$ = $\frac{8}{7}$ x $\frac{50}{29}$
$\frac{32}{y-2007}$= $\frac{8}{7}$ x $\frac{50}{29}$ : $\frac{25}{29}$
$\frac{32}{y-2007}$= $\frac{8 X 50 X 29}{7 X 29 X 25}$
$\frac{32}{y-2007}$ = $\frac{8 X 2 X 25 X 29}{7 X 29 X 25}$
$\frac{32}{y-2007}$ = $\frac{16}{7}$
$\frac{32}{y-2007}$= $\frac{32}{14}$
=> y - 2007 = 14
y = 14 + 2007
y = 2021
Vậy y = 2021
