Làm giúp mình với! Hứa sẽ vote 5 sao
a) 7+( $\frac{7}{12}$ – $\frac{1}{2}$ + 3 ) – ( $\frac{1}{12}$ + 5 )
b) $\frac{3}{4}$ – 0,25 – [ $\frac{7}{3}$ + ( $\frac{-9}{2}$ )] – $\frac{5}{6}$
Làm giúp mình với! Hứa sẽ vote 5 sao a) 7+( $\frac{7}{12}$ – $\frac{1}{2}$ + 3 ) – ( $\frac{1}{12}$ + 5 ) b) $\frac{3}{4}$ – 0,25 – [ $\frac{7}{3
By Melanie
Đáp án:
$a) 7 + (\dfrac{7}{12} -\dfrac{1}{2} +3) – (\dfrac{1}{12} +5)$
$ = 7 + (\dfrac{7}{12} – \dfrac{6}{12} +\dfrac{36}{12} ) – (\dfrac{1}{12} +\dfrac{60}{12})$
$ = 7 + \dfrac{37}{12} – \dfrac{61}{12}$
$ = \dfrac{84}{12} + \dfrac{37}{12}- \dfrac{61}{12}$
$ = 5$
$b) \dfrac{3}{4} – 0,25 – [\dfrac{7}{3} + (-\dfrac{9}{2}) ] – \dfrac{5}{6}$
$ = \dfrac{1}{2} – [ \dfrac{14}{6} – \dfrac{27}{6} ] – \dfrac{5}{6}$
$ = \dfrac{1}{2} +\dfrac{13}{6} – \dfrac{5}{6}$
$ = \dfrac{3}{6} + \dfrac{13}{6} -\dfrac{5}{6}$
$ = \dfrac{11}{6}$
Đáp án:
a) `7 + (\frac{7}{12} – \frac{1}{2}+3)-(\frac{1}{12} + 5)`
`=7 + (\frac{7}{12} – \frac{6}{12}+\frac{36}{12})-(\frac{1}{12} + \frac{60}{12})`
`=7 + \frac{37}{12} -\frac{61}{12}`
`=7 + (-2)`
`=5 `
b) `\frac{3}{4} – 0,25 – [ \frac{7}{3} +(\frac{-9}{2})]-\frac{5}{6}`
`=\frac{3}{4} – \frac{1}{4} – [ \frac{14}{6} +(\frac{-27}{6})]-\frac{5}{6}`
`=\frac{1}{2} + \frac{13}{6} -\frac{5}{6}`
`=\frac{3}{6} + \frac{13}{6} -\frac{5}{6}`
`=\frac{11}{6} `