a: \(4x^3+12=120\)

=>\(4x^3=108\)

=>\(x^3=27=3^3\)

=>x=3

b: \(\left(x-4\right)^2=64\)

=>\(\left[{}\begin{matrix}x-4=8\\x-4=-8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=12\\x=-4\end{matrix}\right.\)

c: (x+1)^3-2=5^2

=>\(\left(x+1\right)^3=25+2=27\)

=>x+1=3

=>x=2

d: 136-(x+5)^2=100

=>(x+5)^2=36

=>\(\left[{}\begin{matrix}x+5=6\\x+5=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=-11\end{matrix}\right.\)

e: \(4^x=16\)

=>\(4^x=4^2\)

=>x=2

f: \(7^x\cdot3-147=0\)

=>\(3\cdot7^x=147\)

=>\(7^x=49\)

=>x=2

g: \(2^{x+3}-15=17\)

=>\(2^{x+3}=32\)

=>x+3=5

=>x=2

h: \(5^{2x-4}\cdot4=10^2\)

=>\(5^{2x-4}=\dfrac{100}{4}=25\)

=>2x-4=2

=>2x=6

=>x=3

i: (32-4x)(7-x)=0

=>(4x-32)(x-7)=0

=>4(x-8)*(x-7)=0

=>(x-8)(x-7)=0

=>\(\left[{}\begin{matrix}x-8=0\\x-7=0\end{matrix}\right.\)

=>\(\left[{}\begin{matrix}x=8\\x=7\end{matrix}\right.\)

k: (8-x)(10-2x)=0

=>(x-8)(x-5)=0

=>\(\left[{}\begin{matrix}x-8=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=8\\x=5\end{matrix}\right.\)

m: \(3^x+3^{x+1}=108\)

=>\(3^x+3^x\cdot3=108\)

=>\(4\cdot3^x=108\)

=>\(3^x=27\)

=>x=3

n: \(5^{x+2}+5^{x+1}=750\)

=>\(5^x\cdot25+5^x\cdot5=750\)

=>\(5^x\cdot30=750\)

=>\(5^x=25\)

=>x=2

\(\left(5x+3\right)\left(2x-1\right)=\left(2x+1\right)\left(5x-2\right)\)

\(\Leftrightarrow5x\left(2x-1\right)+3\left(2x-1\right)=2x\left(5x-2\right)+\left(5x-2\right)\)

\(\Leftrightarrow10x^2-5x+6x-3=10x^2-4x+5x-2\)

\(\Leftrightarrow x-3=x-2\)

\(\Rightarrow\text{vô nghiệm}\)

|5x-1|=(5x-1)⁴

=>|5x-1|=|5x-1|⁴

vì |1|=|1⁴|

|-1|=|-1|⁴

0=|0|⁴

=>5x-1=1 hoặc 5x-1=0 hoặc 5x-1=-1

=>x=2/5 hoặc x=1/5 hoặc x=0

a,x(x-2)+x-2=0

⇔ (x-2)(x+1)=0

⇔ x=2;x=-1

b,x³+x²+x+1=0

⇔ x²(x+1)+x+1=0

⇔ (x+1)(x²+1)=0

⇔ x=-1

nhan tung ve ra roi triet tieu 

làm bừa thui,ai tích mình mình tích lại

Số số hạng là : 

Có số cặp là :

50 : 2 = 25 ( cặp )

Mỗi cặp có giá trị là :

99 - 97 = 2 

Tổng dãy trên là :

25 x 2 = 50

Đáp số : 50

=50

..............học tốt...............

\(\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{\left(5x+1\right).5x+6}=\frac{2005}{2006}\)

\(1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+....+\frac{1}{5x+1}-\frac{1}{5x+6}=\frac{2005}{2006}\)

\(1-\frac{1}{5x+6}=\frac{2005}{2006}\)

\(\frac{1}{5x+6}=1-\frac{2005}{2006}\)

\(\frac{1}{5x+6}=\frac{1}{2006}\)

=>5x+6 = 2006

=>5x = 2000

=>x = 400

x = 400 nha bạn

                       Bài làm :

Ta có :

\(\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{\left(5x+1\right).\left(5x+6\right)}=\frac{2005}{2006}\)

\(\Leftrightarrow\frac{6-1}{1.6}+\frac{11-6}{6.11}+...+\frac{5x+6-5x-1}{\left(5x+1\right).\left(5x+6\right)}=\frac{2005}{2006}\)

\(\Leftrightarrow1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+....+\frac{1}{5x+1}-\frac{1}{5x+6}=\frac{2005}{2006}\)

\(\Leftrightarrow1-\frac{1}{5x+6}=\frac{2005}{2006}\)

\(\Leftrightarrow\frac{1}{5x+6}=1-\frac{2005}{2006}\)

\(\Leftrightarrow\frac{1}{5x+6}=\frac{1}{2006}\)

\(\Leftrightarrow1.2006=\left(5x+6\right).1\)

\(\Leftrightarrow2006=5x+6\)

\(\Leftrightarrow5x=2006-6\)

\(\Leftrightarrow5x=2000\)

\(\Leftrightarrow x=2000\div5=400\)

Vậy x=400

Chúc bạn học tốt !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!