a.  64.4^x=4⁵

4³.4^x=4⁵

4^x=4⁵:4³

4^x=4²

x=2

a,5mũ 36=(5mũ3)mũ12=125 mũ12

11^24=(11^2)12=121^12

vì 121<125 nên 5^36>11^24

cảm ơn nha

a) 89-(73-x)=20

=>73-x=89-20

=>73-x=69

=>x=73-69

=>x=4

A . 89 - ( 73 - x ) = 20

              73 - x   = 89 - 20

              73 - x   = 69

              \(\Rightarrow\)x = 4

B .

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) \(169\div13^2\)

\(=13^2\div13^2\)

\(=13^1\)

\(=13\)

a) 2^x = 16         e)  12^x = 144

2^x = 2⁴                   12^x = 12² 

=> x = 4            => x = 2

b) 2^x+1 = 16     các câu còn lại tương tự nhé nhiều quá

2^x+1 = 2⁴

x + 1 = 4

=> x = 3

c) 5^x+1 = 125

5^x+1 = 5³

x + 1 = 3

=> x = 2

d) 5^{2x - 1} = 125

5^2x-1 = 5³

2x - 1 = 3

2x = 4

=> x = 2

a)Ta có : 2^x = 16 

              2^x  = 2⁴

 =>          x = 4

b) Ta có: 2^x+1 = 16

                2^x+1  = 2⁴

 =>        x+1   = 4

=>           x     = 4-1

=>           x     = 3

Mấy câu sau tương tự vậy đó để hôm khác mình làm tiếp cho bây giờ mình đi ngủ đã buồn ngủ quá hihi ! ^-^

Học tốt nha bạn !

a: \(\frac{4^5\cdot10\cdot5^6+25^5\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}\)

\(=\frac{2^{10}\cdot2\cdot5\cdot5^6+5^{10}\cdot2^8}{2^8\cdot5^4+5^7\cdot2^5}=\frac{2^8\cdot5^7\left(2^3+3^3\right)}{2^5\cdot5^4\left(2^3+3^3\right)}\)

\(=2^3\cdot5^3=10^3=1000\)

b: \(149-\left(35:x+3\right)\cdot17=13\)

=>\(\left(35:x+3\right)\cdot17=149-13=136\)

=>35:x+3=136:17=8

=>35:x=8-3=5

=>\(x=\frac{35}{5}=7\)

c: \(121:11-\left(4x+5:3\right)=4\)

=>11-(4x+5/3)=4

=>4x+5/3=11-4=7

=>\(4x=7-\frac53=\frac{21}{3}-\frac53=\frac{16}{3}\)

=>\(x=\frac{16}{3}:4=\frac43\)

d: \(720:\left\lbrack41-\left(2x-5\right)\right\rbrack=40\)

=>\(41-\left(2x-5\right)=\frac{720}{40}=18\)

=>2x-5=41-18=23

=>2x=28

=>\(x=\frac{28}{2}=14\)

e: Sửa đề: (x+1)+(x+2)+(x+3)+...+(x+100)=5700

=>100x+(1+2+3+...+100)=5700

=>\(100x+100\cdot\frac{101}{2}=5700\)

=>x+50,5=57

=>x=57-50,5

=>x=6,5

Giải:

a) \(4^n:4=64\)

\(\Leftrightarrow4^{n-1}=64\)

\(\Leftrightarrow4^{n-1}=4^3\)

Vì \(4=4\)

Nên \(n-1=3\)

\(\Leftrightarrow n=4\)

b) \(7^5:7^n=49\)

\(\Leftrightarrow7^{5-n}=49\)

\(\Leftrightarrow7^{5-n}=7^2\)

Vì \(7=7\)

Nên \(5-n=2\)

\(\Leftrightarrow n=3\)

c) \(3^n=27\)

\(\Leftrightarrow3^n=3^3\)

Vì \(3=3\)

Nên \(n=3\)

d) \(11^n=121\)

\(\Leftrightarrow11^n=11^2\)

Vì \(11=11\)

Nên \(n=2\)

e) \(5.5^n=125\)

\(\Leftrightarrow5^{1+n}=125\)

\(\Leftrightarrow5^{1+n}=5^3\)

Vì \(5=5\)

Nên \(1+n=3\)

\(\Leftrightarrow n=2\)

g) \(4^n=64:4\)

\(\Leftrightarrow4^n=16\)

\(\Leftrightarrow4^n=4^2\)

Vì \(4=4\)

Nên \(n=2\)

Chúc bạn học tốt!

a) \(4^n\div4=64\)

\(\Rightarrow4^n=64\div4\)

\(\Rightarrow4^n=16\)

\(\Rightarrow4^n=4^2\)

\(\Rightarrow\) n = 2

b) \(7^5\div7^n=49\)

\(\Rightarrow7^5\div7^n=7^2\)

\(\Rightarrow7^n=7^5\div7^2\)

\(\Rightarrow7^n=7^3\)

\(\Rightarrow\) n = 3

c) \(3^n=27\)

\(\Rightarrow3^n=3^3\)

\(\Rightarrow\) n = 3

d) \(11^n=121\)

\(\Rightarrow11^n=11^2\)

\(\Rightarrow\) n = 2

e) \(5\times5^n=125\)

\(\Rightarrow5^n=125\div5\)

\(\Rightarrow5^n=25\)

\(\Rightarrow5^n=5^2\)

\(\Rightarrow\) n = 2

g) \(4^n=64\div4\)

\(\Rightarrow4^n=16\)

\(\Rightarrow4^n=4^2\)

\(\Rightarrow\) n = 2