a: \(20x^2y^3:\left(-4xy^2\right)\)

\(=\left(-\frac{20}{4}\right)\cdot\frac{x^2}{x}\cdot\frac{y^3}{y^2}=-5xy\)

b: \(-\frac12x^4y^4:\frac23x^2y^2\)

\(=\left(-\frac12:\frac23\right)\cdot\frac{x^4}{x^2}\cdot\frac{y^4}{y^2}\)

\(=-\frac34x^2y^2\)

c: \(\left(-xy\right)^6:\left(-xy\right)^3=\left(-xy\right)^{6-3}=\left(-xy\right)^3=-x^3y^3\)

d: \(\left(x+y\right)^2:\left(x+y\right)=\left(x+y\right)^{2-1}=x+y\)

e: \(\left(x-y\right)^5:\left(y-x\right)^4\)

\(=\left(x-y\right)^5:\left(x-y\right)^4\)

\(=\left(x-y\right)^{5-4}=x-y\)

g: \(\left(x-y+z\right)^4:\left(x-y+z\right)^3=\left(x-y+z\right)^{4-3}=x-y+z\)

152 + (-173) - (-18) - 127 

= 152 + (-173) + 18 - 127

= (152 + 18) + (-173) - 127

= 170 + (-300)

= -130

\(152+\left(-173\right)-\left(-18\right)-127\)

\(=\left(152+18\right)-\left(173+127\right)\)

\(=170-300=-130\)

cách 2:

a=\(6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)

a=(6-5-3)-(2/3+5/3-7/3)+(1/2+3/2-5/2)

a=-2-1/2

a=-5/2

Cach 1 jdujsoidfojaiuh

Câu 1:

57x26+57x43+57x31

= 57x(26+43+31)

= 57x100

=5700

Câu 2:

177x 56- 56x56+ 121x44

= (177-56)x 56+ 121x44

= 122x56 + 121x44

= 121x(56+44)

=121x100

=12100

B=1031+743-1031+57

B=(1031-10310)+(743+57)

B=0+800

B=800

\(\sqrt{85}.\sqrt{125}.\sqrt{68}=\sqrt{85.125.68}=\sqrt{5.17.5.25.17.4}\)

\(=\sqrt{5^2.25.17^2.4}=\sqrt{5^2}.\sqrt{25}.\sqrt{17^2}.\sqrt{4}=5.5.17.2=850\)

Bài 3.21:

b: =28+19-28-32+57

=76-32

=44

Bài 1:

1: =15+37+52-37-17=52-2=50

2: =38-42+14-25+27+15=62-42+29=20+29=49

Bài 1: Bỏ ngoặc rồi tính

3) (21-32) - (-12+32)=21-32-(-12)-32=21-32+12-32=-31

4) (12+21) - (23-21+10)=12+21-23+21-10=21

5) (57-725) - (605-53)=57-725-605+53=-1220

6) (55+45+15) - (15-55+45)=55+45+15-15+55-45=55+55=110

Bài 2: Tính các tổng sau một cách hợp lí

1) (-37) + 14 + 26 + 37=(-37+37)+(14+26)=0+40=40

2) (-24) +6 + 10 + 24=(-24+24)+(6+10)=0+16=16

3) 15 + 23 + (-25) + (-23)=(15-25)+(23-23)=-10+0=-10

4) 60 + 33 + (-50) + (-33)=(60-50)+(33-33)=10+0=10

5) (-16) + (-209) + (-14) + 209=(-16-14)+(-209+209)=-30+0=-30

6) (-12) + (-13) + 36 + (-11)=(-11-12-13)+36=-36+36=0