Bài 1
a) Cho a = -1$\frac{2}{3}$ . ( 0,5 – $\frac{2}{3}$ ) và b = 1$\frac{13}{15}$ . (0,5)$^{2}$ . 3
Baì 2 Tìm x, biết
a) 25% + $\frac{1}{3}$ : ( 2x – 1 ) = -5
b) ( $\frac{2}{3}$ x + $\frac{5}{14}$ ) : $\frac{7}{6}$ = $\frac{-3}{4}$
Bài 1 a) Cho a = -1$\frac{2}{3}$ . ( 0,5 – $\frac{2}{3}$ ) và b = 1$\frac{13}{15}$ . (0,5)$^{2}$ . 3 Baì 2 Tìm x, biết a) 25% + $\frac{1}{3}$ : ( 2x
By Ivy
Bài 1
a) a = -1$\frac{2}{3}$ . (0,5-$\frac{2}{3}$) = $\frac{-1}{3}$ . ($\frac{1}{2}$ – $\frac{2}{3}$) = $\frac{-1}{3}$ . ($\frac{-1}{6}$) = $\frac{1}{18}$
b = 1$\frac{13}{15}$ . $0,5^{2}$ . 3 = $\frac{28}{15}$ . ($\frac{1}{2})^{2}$ = $\frac{28}{15}$ . $\frac{1}{4}$ . 3 = $\frac{7}{15}$ . 3 = $\frac{7}{5}$
Bài 2
a) 25% + $\frac{1}{3}$ : (2x-1) = -5 <=> $\frac{1}{4}$ + $\frac{1}{3}$ . $\frac{1}{2x-1}$ = -5 <=> $\frac{1}{3}$ . $\frac{1}{2x-1}$ = -5 – $\frac{1}{4}$ <=> $\frac{1}{6x-3}$ = $\frac{-21}{4}$ <=> 6x – 3 = $\frac{-4}{21}$ <=> 6x = $\frac{59}{21}$ <=> x = $\frac{59}{126}$
b) ($\frac{2}{3}$x + $\frac{5}{14}$) : $\frac{7}{6}$ = $\frac{-3}{4}$ <=> ($\frac{2}{3}$x + $\frac{5}{14}$) . $\frac{6}{7}$ = $\frac{-3}{4}$ <=> $\frac{4}{7}$x + $\frac{15}{49}$ = $\frac{-3}{4}$ <=> $\frac{4}{7}$x = $\frac{-3}{4}$ – $\frac{15}{49}$ <=> $\frac{4}{7}$x = $\frac{-207}{196}$ <=> x = $\frac{-207}{196}$ : $\frac{4}{7}$ <=> x = $\frac{-207}{112}$