a,(38-129+43)-(43+38)=38-129+43-43-38=(38-38)+(43-43)-129=-129

b,-144-[29-(+144)-(-144)=-144-29+144-144=(144-144)-29-144=-173

c)48+|48-174|+(-74)=18+126-74=70

d)(-123+77)-(277-23-123)=-123+77-277+23+123=(-123+123)+(77-277)+23=-200+23=-177

e)-(-57-159)+(43-169)=57+129+43-169=(57+43)+(129-169)=100-40=60

Chúc bạn học tốt( sai chỗ nào cho mjk sr nka??) k cho  mjk nka

bài 2) a) \(2\left(x+1\right)=0\Leftrightarrow x+1=0\Leftrightarrow x=-1\) vậy \(x=-1\)

b) \(x\left(x-2\right)=0\Leftrightarrow\left\{{}\begin{matrix}x=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0\\x=2\end{matrix}\right.\) vậy \(x=0;x=2\)

c) \(\left(x-1\right)\left(x+7\right)=0\Leftrightarrow\left\{{}\begin{matrix}x-1=0\\x+7=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\x=-7\end{matrix}\right.\) vậy \(x=1;x=-7\)

d) \(\left(x+2\right)\left(x^2-9\right)=0\Leftrightarrow\left\{{}\begin{matrix}x+2=0\\x^2-9=0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=-2\\x^2=9\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=-2\\\left\{{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\end{matrix}\right.\) vậy \(x=-2;x=3;x=-3\)

e) \(x^2\left(x-5\right)+2\left(x-5\right)=0\Leftrightarrow\left(x^2+2\right)\left(x-5\right)=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}x^2+2=0\\x-5=0\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x\in\varnothing\\x=5\end{matrix}\right.\) vậy \(x=5\)

bài 1) \(A=48+\left(-48-174\right)+\left|-74\right|=48-48-174+74=-100\)

\(B=\left(-123\right)+77+\left(-257\right)-23-43=-123+77-257-23-43=-369\)

\(C=\left(-57\right)+\left(-159\right)+47+169=-57-159+47+169=0\)

quá hợp lí

a: =-48+27+56-48-27-36

=-96+20

=-76

b: =23-57+57-33=-10

c: =-98+12-159-12-41

=-98-200

=-298

a: =48+174-48-74=100

b: =-123+23+77-257-43

=-100-200-43=-343

c: \(=\left(-57+47\right)+\left(-159+169\right)=-10+10=0\)

d: \(=100\cdot\left(-47\right)+53\cdot\left(-100\right)\)

\(=100\cdot\left(-100\right)=-10000\)

a, ( - 5 ) . ( - 7 ) . 4 . 20 . ( - 25 )

= -70000

 b, ( - 16 ) . 73 + ( - 16 ) . 27

= -1600

c, ( - 48 ) . 159 - ( - 48 ) . 59

= -4800

d , 72 . ( - 83 ) + ( - 72 ) . ( - 125 )

= 3014

e , ( - 81 ) . 125 - 181 . ( - 125 )

= 12500

#Hoctot

a -70000.0000 

b-1600.000000

c-4800.000000

d-4968.000000

e-12500.00000

a, 70000

b, 1600

c, 4800

d, 3014

e, 12500

a) \(...=16.\left(36-37\right)=16.\left(-1\right)=-16\)

b) \(...=9.3+9.50=9.\left(3+50\right)=9.53=477\)

c) \(...=2.\left(\left(5.16-18\right)+36:18\right)=2.\left(70+2\right)=2.72=144\)

d) \(...=5\left(48:8+44\right)=5\left(6+44\right)=5.50=250\)

e) \(...=20-6=14\) 

f) \(...=50+13-2=61\)

Cô tick xanh cho bạn Đức Trí, các câu khác em làm theo bạn vì bạn làm đúng còn câu c em làm theo cô nhé.

Câu c, 

    2.(5.16 - 18) + 36:18.2

= 2.(80 - 18) + 2.2

= 2.62 + 4

= 128

d) 48 : 8 . 5 + 5 . 44

= 6 . 5 + 5 . 44

= 5 . (6 + 44)

= 5 . 50

= 250

e) 5 . 4 - 18 : 3

= 20 - 6

= 14

f) 2 . 25 + 169 : 13 - 54 : 27

= 50 + 13 - 2

= 61

\(a,\left(-37-17\right).\left(-9\right)+35.\left(-9-11\right)\)

\(=\left(-54\right).\left(-9\right)+35.\left(-20\right)\)

\(=486+\left(-700\right)\)

\(=-214\)

\(b,\left(-25\right).\left(75-25\right)-75.\left(45-25\right)\)

\(=\left(-25\right).50-75.20\)

\(=\left(-25\right).50+\left(-25\right).3.20\)

\(=\left(-25\right).50+\left(-25\right).60\)

\(=\left(-25\right).\left(50+60\right)\)

\(=\left(-25\right).110\)

\(=-2750\)

\(c,136.\left(-47\right)+36.47\)

\(=47.\left(-136+36\right)\)

\(=47.\left(-100\right)\)

\(=-4700\)