a: \(-15-\left(-13+30\right)\)

\(=-15+13-30\)

\(=\left(-15-30\right)+13\)

=-45+13

=-32

b: \(225-150:\left(30+3^2\cdot5\right)\)

\(=225-150:\left(30+9\cdot5\right)\)

\(=225-150:75\)

=225-2

=223

c: \(18\cdot64+18\cdot36-1200\)

\(=18\left(64+36\right)-1200\)

\(=18\cdot100-12\cdot100\)

\(=6\cdot100=600\)

d: \(80-\left[130-\left(12-4\right)^2\right]\)

\(=80-130+\left(12-4\right)^2\)

\(=-50+8^2=64-50=14\)

thanks

a) 5. 4² - 18 : 3² =  5 . 16  -18 : 9 = 80 - 2 = 78

b) 3³ .18 -3³ .12 = 3³ . 6 =  27 .6 = 162

c) 39 . 213 + 87 . 39 = 39 . ( 213 + 87 ) = 39 . 300 = 11700

d) 80 - [ 130 - ( 12 - 4 ) .2 ] = 80 - (130 - 8.2 ) = 80 - 114 = -34

OK

bạn kia làm đúng giồi

cho mình 1 lai nhe

ko bit

a, 20^2 - 6^ 2=  400 - 36 = 364

b,3^3 . 18 - 3^3 . 12 = 3^3 . ( 18-12) = 27 . 6 = 162

c, 39 . 213 + 87 . 39 = ( 213 + 87) . 39 = 300 . 39 = 110700

d, 80 - [ 130 - ( 12 - 4)^2] = 80 - [130 - (3^2) ] = 80 - 130 - 9 = -59

1. 2².3².5:2².3-3²=3.5-3²=15-9=6
2. 2.5²-2².3²:3²=2.(5²-2)=2.(25-2)=46

3. 3³.19-3³.12=3³.(19-12)=3³.7=189

4. 3.5²-16:2²=3.5²-2⁴:2²=3.25-4=75-4=71

Bài 1 :

\(M=\dfrac{30-2^{20}}{2^{18}}=\dfrac{2.15-2^{20}}{2^{18}}=\dfrac{15}{2^{17}}-2^2=\dfrac{15}{2^{17}}-4< 0\left(\dfrac{15}{2^{17}}< 1\right)\)

\(N=\dfrac{3^5}{1^{2021}+2^3}=\dfrac{3^5}{9}=\dfrac{3^5}{3^2}=3^3=27\)

\(\Rightarrow M< N\)

Bài 3 :

a) \(t^2+5t-8\) khi \(t=2\)

\(=5^2+2.5-8\)

\(=25+10-8\)

\(=27\)

b) \(\left(a+b\right)^2-\left(b-a\right)^3+2021\left(1\right)\)

\(\left\{{}\begin{matrix}a=5\\b=a+1=6\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}a+b=11\\b-a=1\end{matrix}\right.\)

\(\left(1\right)=11^2-1^3+2021=121-1+2021=2141\)

c) \(x^3-3x^2y+3xy^2-y^3=\left(x-y\right)^3\left(1\right)\)

\(\left\{{}\begin{matrix}x=3\\y=2\end{matrix}\right.\) \(\Rightarrow x-y=1\)

\(\left(1\right)=1^3=1\)

1: \(78+22+18\)

\(=\left(78+22\right)+18\)

=100+18

=118

2: \(94+563+\left(106-563\right)-\left(-70\right)\)

\(=94+563+106-563+70\)

\(=\left(94+106\right)-\left(563-563\right)+70\)

=100-0+70

=170

3: \(25\cdot154-25+47\cdot25\)

\(=25\left(154-1+47\right)\)

\(=25\cdot200=5000\)

4: \(\left[5^{29}+5^{30}\left(16-11\right)\right]:5^{29}\)

\(=\left(5^{29}+5^{30}\cdot5\right):5^{29}\)

\(=\dfrac{5^{29}\cdot1+5^{29}\cdot5^2}{5^{29}}\)

\(=1+5^2=26\)

8: \(25\cdot2^3-\left(9-14\right)+\left(29-34+20\right)\)

\(=25\cdot8-\left(-5\right)+\left(-5\right)+20\)

\(=200+5-5+20\)

=220

1,a, 33-13(-18)=33-(-234)=267

b, 160.53+47.160=160.(53+47)=160.100=16000

c, 180:{150:[100:(24.2-4².3)]}

=180:{150:[100:(24.2-16.3)]}

=180:{150:[100:(48-48)]}

=180:[150:(100:0)] (loại vì ko có stn nào nhân vs 0 = 100)

d,43-23+(-11)=10+(-11)=-1

e,120.64+36.120=120.(64+36)=120.100=12000

g, 15.{72:[100-(12+4⁵:4²)]}

=15.{72:[100-(12+4³)]}

=15.{72:[100-(12+64)]}

=15.[72:(100-76)]

=15.(72:24)

=15.3=45

2,a, x-36=82

x=82+36=118

b, (2x+4).8-40=24

(2x+4).8=24+40

(2x+4).8=64

2x+4=64:8

2x+4=8

2x=8-4

2x=4

x=4:2=2

c, (2x+4²)-2⁵=64:2⁴

(2x+16)-32=64:16

(2x+16)-32=4

2x+16=4+32

2x+16=36

2x=36-16

2x=20

x=20:2=10

d, 95-x=45

x=95-45=50

e, (2x+13)-2=47-17

(2x+13)-2=30

2x+13=30+2

2x+13=32

2x=32-13

2x=19

x=19:2=9,5

g, (2x+3²)-8=50:2

(2x+9)-8=25

2x+9=25+8

2x+9=33

2x=33-9

2x=24

x=24:2=12

c) Ta có: \(\dfrac{3}{5}+\dfrac{-5}{20}+\dfrac{30}{75}+\dfrac{-7}{4}\)

\(=\dfrac{3}{5}+\dfrac{2}{5}+\dfrac{-1}{4}+\dfrac{-7}{4}\)

\(=1-2=-1\)

Giải:

a)-1/12+4/3=-1/12+16/12=15/12=5/4

b)(-4/14-3/15)-(1/5-20/35-(-1)).7

=-17/35-22/35.7

=-17/35-22/5

=-171/35

c)3/5+-5/20+30/75+-7/4

=3/5+-1/4+2/5+-7/4

=(3/5+2/5)+(-1/4+-7/4)

=1+-2

=-1

d)5/6.-12/14+7/13

=-5/7+7/13

=-16/91

e)2/-9-5/-36-1/4

=-1/12-1/4

=-1/3

f)2/23+-5/12+7/18+21/23+-7/12

=(2/23+21/23)+(-5/12+-7/12)+7/18

=1+-1+7/18

=7/18