1.
a)$\frac{-1}{8}$ + $\frac{-5}{3}$
b)$\frac{-6}{35}$ x $\frac{-49}{54}$
c)$\frac{-4}{5}$ : $\frac{-3}{4}$
d)$\frac{31}{17}$ + $\frac{-5}{13}$ + $\frac{-8}{13}$ – $\frac{14}{17}$
2.
a)$\frac{4}{5}$.x=$\frac{4}{7}$
b)$\frac{3}{4}$:x=$\frac{1}{2}$
gấp
Giải thích các bước giải:
B1)
a)`-1/8“+“-5/3`
`=“-3/24“+“-40/24`
`=“-43/24`
b)`-6/35“ד-49/54`
`=“7/45`
c)`-4/5“:“-3/4`
`=“-4/5“ד4/-3`
`=“3/5`
d)`31/17“+“-5/13“+“-8/13“-“14/17`
`=“(`31/17“-“14/17`)`+`(`-5/13“+“-8/13`)
`=“1“+“(-1)`
`=“0`
B2)
a)`4/5“.“x“=“4/7`
⇒`x“=`4/7“÷`4/5`
⇒`x“=“16/35`
b)`3/“4÷“x“=“1/2`
⇒`x“=“3/4“÷“1/2`
⇒`x“=“3/2`
B1)
a)-1/8+-5/3
=-3/24+-40/24
=-43/24
b)-6/35×-49/54
=7/45
c)-4/5:-3/4
=-4/5×4/-3
=3/5
d)31/17+-5/13+-8/13-14/17
=(31/17-14/17)+(-5/13+-8/13)
=1+-1
=0
B2)
a)4/5.x=4/7
⇒x=4/7÷4/5
⇒x=16/35
b)3/4÷x=1/2
⇒x=3/4÷1/2
⇒x=3/2
CHúc bạn học tốt !