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a,\(\dfrac{3^6.5^7.7^{11}}{3^4.5^7.7^{10}}=\dfrac{3^4.3^2.5^7.7^{10}.7}{3^4.5^7.7^{10}}\) \(=9.7=63\)
b,\(\dfrac{2^{43}+2^4}{2^{39}+1}=\dfrac{2^{39}.2^4+2^4}{2^{39}+1}\) \(=\dfrac{2^4\left(2^{39}+1\right)}{2^{39}+1}=16\)

a) 7.x - x = 521 : 519 + 3.22 - 70
6x = 25 + 12 - 1
6x = 36
x = 6
b) 7x - 2x = 617 : 615 + 44 : 11
5x = 36 + 4
5x = 40
x = 8
c) 5x + x = 39 - 311 : 39
6x = 39 - 9
6x = 30
x = 5
d) [(6x - 39) : 7]. 4 = 12
(6x - 39) : 7 = 12 : 4
(6x - 39) : 7 = 3
6x - 39 = 3 . 7
6x - 39 = 21
6x = 21 + 39
6x = 60
x = 10
x =

a,\(5^3.2-100:4+2^3.5\)
= 125 . 2 - 25 + 8 . 5
= 250 - 25 + 40
= 265
b, \(6^2:9+50.2-3^3.3\)
= 36 : 9 + 100 - 27 . 3
= 4 + 100 - 81
= 23
b) \(5^3\cdot2-100:4+2^3\cdot5\)
\(=125\cdot2-25+8\cdot5\)
\(=250-25+40\)
\(=225+40=265\)
c) \(6^2:9+50\cdot2+3^3-3\)
\(=36:9+100+27-3\)
\(=4+100+27-3\)
\(=104+27-3=131-3=128\)
d) \(3^2\cdot5+2^3\cdot10-81:3\)
\(=9\cdot5+8\cdot10-27\)
\(=45+80-27\)
\(=125-27=98\)
e) \(5^{13}:5^{10}-25\cdot2^2\)
\(=5^{13-10}-5^2\cdot2^2\)
\(=5^3-\left(5\cdot2\right)^2\)
\(=125-10^2\)
\(=125-100=25\)
f) \(20:2^2+5^9:5^8\)
\(=20:4+5^{9-8}\)
\(=5+5^1=5+5=10\)
g) \(100:5^2+7\cdot3^2\)
\(=10^2:5^2+7\cdot9\)
\(=\left(10:5\right)^2+63\)
\(=2^2+63=4+63=67\)
h) \(84:4+3^9:3^7+5^0\)
\(=21+3^{9-7}+1\)
\(=21+3^2+1\)
\(=21+9+1=30+1=31\)
i) \(29-\left[16+3\cdot\left(51-49\right)\right]\)
\(=29-\left[16+3\cdot2\right]\)
\(=29-\left[16+6\right]\)
\(=29-22=7\)
j) \(\left(15^{19}:5^{17}+3\right)\cdot0:7\)
\(=\left[\left(3\cdot5\right)^{19}:5^{17}+3\right]\cdot0\)
Vì số nào nhân cho 0 cũng bằng 0 nên giá trị biểu thức trên bằng 0
k) \(7^9:7^7-3^2+2^3\cdot5\)
\(=7^{9-7}-9+8\cdot5\)
\(=7^2-9+40\)
\(=49-9+40=40+40=80\)
l) \(1200:2+6^2\cdot2^1+18\)
\(=600+36\cdot2+18\)
\(=600+72+18\)
\(=600+\left(72+18\right)=600+90=690\)
m) \(5^9:5^7+70:14-20\)
\(=5^{9-7}+5-20\)
\(=5^2+5-20\)
\(25+5-20=30-20=10\)
Những câu sau mình làm sau nhé bạn!!!!!!!

a) \(27^7\div9^{10}\)
\(=\left(3^3\right)^7\div\left(3^2\right)^{10}\)
\(=3^{3\times7}\div3^{2\times10}\)
\(=3^{21}\div3^{20}\)
\(=3^1\)
\(=3\)
b) \(125^6\div25^7\)
\(=\left(5^3\right)^6\div\left(5^2\right)^7\)
\(=5^{3\times6}\div5^{2\times7}\)
\(=5^{18}\div5^{14}\)
\(=5^4\)
\(=625\)
c) \(5^{15}\div5^3\)
\(=5^{12}\)
\(=244140625\)
d) \(11^7\div11^3\)
\(=11^4\)
\(=14641\)
e) \(125\div5^2\)
\(=5^2\div5^2\)
\(=5^1\)
\(=5\)
g) \(169\div13^2\)
\(=13^2\div13^2\)
\(=13^1\)
\(=13\)

Bạn ơi trả lời nhanh hộ mình với mình chỉ còn 1 ngày làm bài thôi các bạn ah
ko biết mk làm có đúng ko nhé tham khỏa thôi
A= (62019-62018):62018 B=(72020+72019) : 72019
= 62019 : 62018-62018 : 62018 = 72020:72019+72019:72019
= 61 - 60 =71+70
= 6-1=5 =7+1=8

a, \(S=3^0+3^2+3^4+3^6+...+3^{2020}\)
\(\Leftrightarrow3^2S=3^2+3^4+3^6+3^8+...+3^{2022}\)
\(\Leftrightarrow3^2S-S=3^{2022}-3^0\)
\(\Leftrightarrow9S-S=3^{2022}-1\)
\(\Leftrightarrow8S=3^{2022}-1\Leftrightarrow S=\frac{3^{2022}-1}{8}\)
b,\(S=3^0+3^2+3^4+3^6+...+3^{2020}\)
\(=\left(3^0+3^2+3^4\right)+\left(3^6+3^8+3^{10}\right)+...+\left(3^{2016}+3^{2018}+3^{2020}\right)\)
\(=\left(1+3^2+3^4\right)+3^6\left(1+3^2+3^4\right)+...+3^{2016}\left(1+3^2+3^4\right)\)
\(=\left(1+3^2+3^4\right)\left(1+3^6+...+3^{2016}\right)\)
\(=91\left(1+3^6+...+3^{2016}\right)=13.7\left(1+3^6+...+3^{2016}\right)⋮7\)
=> đpcm
Tham khảo :
a, S=30+32+34+36+...+32020S=30+32+34+36+...+32020
⇔32S=32+34+36+38+...+32022⇔32S=32+34+36+38+...+32022
⇔32S−S=32022−30⇔32S−S=32022−30
⇔9S−S=32022−1⇔9S−S=32022−1
⇔8S=32022−1⇔S=32022−18⇔8S=32022−1⇔S=32022−18
b,S

câu a:
3\(^2\) x 5 + 2\(^3\) x 10 - 81 : 3
= 9 x 5 + 8 x 10 - 27
= 45 + 80 - 27
= 125 - 27
= 98
Câu c:
100 : 5\(^2\) + 7 x 3\(^2\)
= 100 : 25 + 7 x 9
= 4 + 63
= 67

\(\text{7x - x = 5}^{21}:5^{19}+3.2^2-7^0\)
\(\text{(7-1)x=5}^2\text{ + 3. 4 - 1}\)
\(\text{6x = 25 + 12 - 1}\)
\(\text{6x = 36}\)
\(\text{ x = 6}\)
a)7.x-x=521 :519 +3.22 -70
x.(7-1)=52+12-1
x.6 =36
x =36:6=6
b)7.x-2.x=617:615+44:11
x.(7-2)=62+4
x.5 =40
x=40:5=8
\(A=7^{15}:7^{13}-2020^0\\ \Rightarrow A=7^2-1\\ \Rightarrow A=48.\)