Ta có: \(\left(-\dfrac{3}{2}\right)^3+\dfrac{-49}{24}\cdot\dfrac{3}{14}-\left(\dfrac{5}{8}-\dfrac{27}{8}\right)\)

\(=\dfrac{-27}{8}+\dfrac{-7}{2}\cdot\dfrac{1}{8}-\dfrac{-22}{8}\)

\(=\dfrac{-27+22}{8}+\dfrac{-7}{16}\)

\(=\dfrac{-5}{8}+\dfrac{-7}{16}\)

\(=\dfrac{-10}{16}+\dfrac{-7}{16}\)

\(=\dfrac{-17}{16}\)

a) 49.(-34)+(-65).49-49 = 49. (-34-65-1)= 49. (-100)= -4900

b) -268-(-47-168)-147 = (-268 + 168) - (147 - 47)= -100 -100=-200

c) (-2)².(-3)-[(-1)²⁰²⁴+8]:(-3)² = 4. (-3) - [1 +8]:9 = -12 - 9:9 = -12 - 1 = -13

d) 67-[8+7.3² -24:6+(9-7)³]:15 = 67 - [8 + 7.9 - 4 + 2³ ] : 15

= 67 - [8+63-4+8]:15 = 67 - 75:15 = 67 - 5 = 62

\(b,\Leftrightarrow x+7=38\Leftrightarrow x=31\\ c,\Leftrightarrow\left[{}\begin{matrix}x=7\\x=-7\end{matrix}\right.\\ d,\Leftrightarrow2x=160-49=111\Leftrightarrow x=\dfrac{111}{2}\\ e,\Leftrightarrow x-8=20\Leftrightarrow x=28\\ f,\Leftrightarrow x-3=\dfrac{59}{4}\Leftrightarrow x=\dfrac{71}{4}\\ g,\Leftrightarrow x=3\\ h,\Leftrightarrow2x+1=5\Leftrightarrow2x=4\Leftrightarrow x=2\)

a)\(\left(\frac{25}{49}+\frac{17}{39}+\frac{22}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\left(\frac{17}{39}+\frac{22}{39}\right)\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\frac{39}{39}\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+1\times\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\left(\frac{25}{49}+\frac{25}{49}\right)\times\frac{41}{25}\)

\(=\frac{50}{49}\times\frac{41}{25}\)

\(=\frac{2050}{1225}\)

`15+20-30=5`

`5+8-9=4`

`45-8+12=49`

`49-49=0`

`=> 5+4+49=58`.

thanks

15+20-30=5

3+8-9=2

45-8+12=49

53-49=4

5+2+49+4=60

Chúc bạn học tốt.

mình còn ko bt cơ mà mai nộp r

mik chỉ lm đc 1 câu thôi mong bn like cho
(13911:3849−5211:3849):(4938.511)={(13+911).4938−(5+211).4938}:(4938.511)=4938.(13−5+911−211):(4938.511)=4938.(8+711):(4938.511)=(8+711):511=19