a) (-2)+ (-5) = -7

Vì: -7< -5

=> (-2)+ (-5) < -7

b) (-3)+ (-8)= -11

Vì: (-10) > (-11)

=> -10> (-3)+ (-8)

a)(-2)+(-5)<(-5)

b)(-10)>(-3)+(-8)

a) \(\left(-2\right)+\left(-5\right)..........\left(-5\right)\)

\(\left(-7\right)< \left(-5\right)\)

Vậy \(\left(-2\right)+\left(-5\right)< \left(-5\right)\)

b) \(\left(-10\right)...........\left(-3\right)+\left(-8\right)\)

\(\left(-10\right)>\left(-11\right)\)

Vậy \(\left(-10\right)>\left(-3\right)+\left(-8\right)\)

a) $\left(-2\right).3....>\; hoặc\; \backslash (\backslash ge\backslash ).....\left(-2\right).5$

b) $4.\left(-2\right)...<\; hoặc\; \backslash (\backslash le\backslash )....\left(-7\right).\left(-2\right)$

c) ${\left(-6\right)}^2+\mathrm{2....\backslash (\backslash le\backslash )\; hoặc\; \backslash (\backslash ge\backslash )....36}+2$

d) $5.\left(-8\right).....>\; hoặc\; \backslash (\backslash ge\backslash ).....135.\left(-8\right)$

a)ta có:(-2).3=-6 ; (-2).5=-10

Vì -6>-10 nên (-2).3>(-2).5

b)Ta có:4.(-2)=-8 ; (-7).(-2)=14

vì -8<14 nên 4.(-2)<(-7).(-2)

c)Ta có:(-6)²+2=36+2=38 ; 36+2=38

Vì 38=38 nên (-6)²+2=36+2

d)Ta có:5.(-8)=-40 ; 135.(-8)=-1080

Vì -40>-1080 nên 5.(-8) > 135.(-8)

1. \(\frac{2}{3}x^3y^4\left(-3x^4y^5\right)=-2x^7y^9\)

2. \(\left(-2x^5\right)\left(7xy^3\right)=-14x^6y^3\)

Kb nha

a)( -11) .(8.9)= (-11) .8 - (-11) .9= 11

b) (-12).10 - (-9) . 10= [ -12 - (-9) ] . 10 = -30

a) \(\left(-11\right)\cdot\left(8-9\right)=\left(-11\right)\cdot8-\left(-11\right)\cdot9=11\)

b) \(\left(-12\right)\cdot10-\left(-9\right)\cdot10=\left[-12-\left(-9\right)\right]\cdot10=-30\)

a) ( -11 ) . ( 8 - 9 ) = ( -11 ).8 - (-11).9 = 11

b) ( -12 ) . 10 - ( - 9 ) .10 = [ - 12 - ( -9 )] . 10 = -30

\(a\)) \(\left|3\right|< \left|5\right|\)

\(b\))\(\left|-3\right|< \left|-5\right|\)

\(c\)) \(\left|-1\right|>\left|0\right|\)

\(\left|2\right|=\left|-2\right|\)

a)

\(\begin{array}{l}\left( {9x - {2^3}} \right):5 = 2\\9x - {2^3} = 2.5\\9x - 8 = 10\\9x = 18\\x = 2\end{array}\)

Vậy \(x = 2\)

b)

\(\begin{array}{l}\left[ {{3^4} - \left( {{8^2} + 14} \right):13} \right]x = {5^3} + {10^2}\\\left[ {81 - \left( {64 + 14} \right):13} \right]x = 125 + 100\\\left[ {81 - 78:13} \right]x = 125 + 100\\\left[ {81 - 6} \right]x = 225\\75x = 225\\x = 3\end{array}\)

Vậy \(x = 3\)

A = - 5²² - { - 222 - [ - 122 - (100 - 5²²) + 2022] }

A = - 5²² - { -222 - [- 122 - 100 + 5²² ] + 2022}

A = - 5²² - { -222 - { - 222 + 5²² } + 2022}

A = - 5²² - {- 222 + 222 - 5²² + 2022}

A = -5²² + 5²² - 2022

A = - 2022

B = 1 + \(\dfrac{1}{2}\)(1 + 2) + \(\dfrac{1}{3}\).(1 + 2 + 3) + ... + \(\dfrac{1}{20}\).(1 + 2+ 3 + ... + 20)

B = 1+\(\dfrac{1}{2}\)\(\times\)(1+2)\(\times\)[(2-1):1+1]:2+ ... + \(\dfrac{1}{20}\)\(\times\) (20 + 1)\(\times\)[(20-1):1+1]:2

B = 1 + \(\dfrac{1}{2}\) \(\times\) 3 \(\times\) 2:2 + \(\dfrac{1}{3}\) \(\times\)4 \(\times\) 3 : 2+....+ \(\dfrac{1}{20}\) \(\times\)21 \(\times\) 20 : 2

B = 1 + \(\dfrac{3}{2}\) + \(\dfrac{4}{2}\) + ....+ \(\dfrac{21}{2}\)

B = \(\dfrac{2+3+4+...+21}{2}\)

B = \(\dfrac{\left(21+2\right)\left[\left(21-2\right):1+1\right]:2}{2}\)

B = \(\dfrac{23\times20:2}{2}\)

B = \(\dfrac{23\times10}{2}\)

B = 23 

\(a,=5^3:5^2=5\\ b,=\left(\dfrac{3}{4}\right)^{5-3}=\left(\dfrac{3}{4}\right)^2=\dfrac{9}{16}\\ c,=1728-512=1216\\ d,=x^{10}:x^8=x^2\\ e,=\left(-x\right)^{5-3}=\left(-x\right)^2=x^2\\ f,=\left(-y\right)^{5-4}=-y\)