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

b) 3³ . 18 – 3³ . 12 = 27 . 18 - 27 . 12 = 486 - 324 = 162;

Lưu ý. Có thể áp dụng tính chất phân phối của phép nhân đối với phép cộng:

3³ . 18 – 3³ . 12 = 3³ (18 - 12) = 27 . 6 = 162;

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

d) 80 – [130 – (12 – 4)²] = 80 - (130 - 64) = 80 - 66 = 14.

a)=78

b)=162

c)=11700

d)=14

a, 6^2 : 4 . 3 + 2 . 5^2

= 36 : 12 + 2 . 25

= 4 + 50

= 54

b, 5 . 4^2 - 18 : 3^2

= 5 . 16 - 18 : 9

= 80 - 2

= 78

a) \(6^2:4\cdot3+2\cdot5^2\)

\(=36:4\cdot3+2\cdot25\)

\(=9\cdot3+2\cdot25\)

\(=27+50\)

\(=77\)

\(77=7\cdot11\)

b) \(5\cdot4^2-18:3^2\)

\(=5\cdot16-18:9\)

\(=80-2\)

\(=78\)

\(78=2\cdot3\cdot13\)

a) \(3^{7} \cdot 27^{5} \cdot 81^{3}\)

• Đổi về cơ số 3: \(27 = 3^{3} , \textrm{ }\textrm{ } 81 = 3^{4}\).

\(3^{7} \cdot \left(\right. 3^{3} \left.\right)^{5} \cdot \left(\right. 3^{4} \left.\right)^{3} = 3^{7} \cdot 3^{15} \cdot 3^{12} = 3^{7 + 15 + 12} = 3^{34} .\)

b) \(100^{6} \cdot 1000^{5} \cdot 10 \textrm{ } 000^{3}\)

• Đổi về cơ số 10: \(100 = 10^{2} , \textrm{ }\textrm{ } 1000 = 10^{3} , \textrm{ }\textrm{ } 10 \textrm{ } 000 = 10^{4}\).

\(\left(\right. 10^{2} \left.\right)^{6} \cdot \left(\right. 10^{3} \left.\right)^{5} \cdot \left(\right. 10^{4} \left.\right)^{3} = 10^{12} \cdot 10^{15} \cdot 10^{12} = 10^{39} .\)

c) \(\frac{36^{5}}{18^{5}}\)

• Do cùng số mũ:

\(\left(\left(\right. \frac{36}{18} \left.\right)\right)^{5} = 2^{5} = 32.\)

d) \(24 \cdot 5^{2} + 5^{2} \cdot 5^{3}\)

\(= 24 \cdot 25 + 25 \cdot 125 = 600 + 3125 = 3725.\)

e) \(\frac{125^{4}}{5^{8}}\)

• Đổi về cơ số 5: \(125 = 5^{3}\).

\(\left(\right. 5^{3} \left.\right)^{4} : 5^{8} = 5^{12} : 5^{8} = 5^{12 - 8} = 5^{4} = 625.\)

TÓM lại là a) \(3^{34}\)
b) \(10^{39}\)
c) \(32\)
d) \(3725\)
e) \(625\)

bạn muốn chép đáp án hay sem cách làm///??

a: \(3^7\cdot27^5\cdot81^3\)

\(=3^7\cdot\left(3^3\right)^5\cdot\left(3^4\right)^3\)

\(=3^7\cdot3^{15}\cdot3^{12}=3^{7+15+12}=3^{34}\)

b: \(100^6\cdot1000^5\cdot10000^3\)

\(=\left(10^2\right)^6\cdot\left(10^3\right)^5\cdot\left(10^4\right)^3\)

\(=10^{12}\cdot10^{15}\cdot10^{12}=10^{15+12+12}=10^{39}\)

c: \(36^5:18^5=\left(\frac{36}{18}\right)^5=2^5=32\)

d: \(24\cdot5^2+5^2\cdot5^3\)

\(=5^2\left(24+5^3\right)\)

\(=25\cdot\left(24+125\right)=25\cdot149=3725\)

e: \(125^4:5^8=\left(5^3\right)^4:5^8=5^{12}:5^8=5^{12-8}=5^4\)

a, = 1

b = 99/100

c = -17/99999995

b) \(\frac{1}{2}+\frac{1}{2.3}+...+\frac{1}{99.100}\)

\(\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\)

\(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)

\(1-\frac{1}{100}=\frac{99}{100}\)

Bằng 25/24 nhé bạn mk nhanh nhất tk cho mk nhé

= 25/24

ko tk nha giúp thôi !!!

1/ \(\frac{3}{5}=\frac{60}{100}=60\%\)

\(\frac{9}{12}=\frac{75}{100}=75\%\)

2/     \(18\frac{13}{19}+31\frac{8}{19}-\frac{2}{19}\)

\(=18\frac{13}{19}+31\frac{6}{19}\)

\(=\left(18+31\right)\frac{13}{19}+\frac{6}{19}\)

\(=49\frac{19}{19}\)

a) 18 + 36 : 3²

= 18 + 36 : 9

= 18 + 4

= 22

b) 2³ . 81 + 2³ . |-19|

= 2^3 . 81 + 2^3 . 19

= 2^3 ( 81 + 19 )

= 2^3 . 100

= 8 . 100

= 800

c) 2^3 . 5 - [ 6^2 : 4 + 3 ( 2^3 - 5 )]

= 8 . 5 - [ 36 : 4 + 3 ( 8 - 5 )]

= 40 - ( 36 : 4 + 3 . 3 )

= 40 - ( 9 + 9 )

= 40 - 18

= 22

a,18+36:3²

=18+36:9

=18+4

=22

-3/18-12/9

=-1/6+-4/3

=-1/6+-8/6

=-9/6

=-3/2

-49/115:7/-115

=-49/115x-115/7

=7

a)   -3/18 -12/9

=  -1/6 - 4/3

=  -1/6 - 8/6

= -1-8/6

= -9/6

= -3/2

= -1/1/2 

a: \(=36:4+2\cdot25=9+50=59\)

b: \(=79\left(82+18\right)=79\cdot100=7900\)

c: \(=49-9-\left(4^2+2^2\right)\)

\(=40-16-4=40-20=20\)

d: \(=16+\left[400:\left(200-42-138\right)\right]\)

\(=16+400:20=16+20=36\)

a.\(12^7:6^7=\left(12:6\right)^7=2^7\)

b. \(27^5:81^3=\left(3^3\right)^5:\left(3^4\right)^3=3^{15}:3^{12}=3^3\)

c. \(18^3:9^3=\left(18:9\right)^3=2^3\)

d. \(125^3:25^4=\left(25^3\right)^3:25^4=25^9:25^4=25^5\)

12^7:6^7=(12:6)^7=2^7

27^5:81^3=(3^3)^5:(3^4)^3=3^15:3^12=3^3

18^3:9^3=(18:9)^3=2^3

125^3:25^4=(5^3)^3:(5^2)^4=5^9:5^8=5