tim x biet x *5,2- x=4,2 *

\(0,2-\left|4,2-2x\right|=0\)

\(\Leftrightarrow\left|4,2-2x\right|=0,2\)

\(\Leftrightarrow\orbr{\begin{cases}4,2-2x=0,2\\4,2-2x=-0,2\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2\\x=2,2\end{cases}}\)

Vậy \(x\in\left\{2;2,2\right\}\)

\(0,2-\left|4,2-2x\right|=0\)

\(\Rightarrow\left|\frac{21}{5}-2x\right|=\frac{1}{5}\)

\(\Rightarrow\orbr{\begin{cases}\frac{21}{5}-2x=\frac{1}{5}\\\frac{21}{5}-2x=-\frac{1}{5}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x=4\\2x=\frac{22}{5}\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=2\\x=\frac{11}{5}\end{cases}}\)

\(0,2-\left|4,2-2x\right|=0\)

\(\Leftrightarrow\left|4,2-2x\right|=0,2\)

\(\Leftrightarrow\orbr{\begin{cases}4,2-2x=0,2\\4,2-2x=-0,2\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}2x=4,2-0,2\\2x=4,2+0,2\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}2x=4\\2x=4,4\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=2,2\end{cases}}\)

0,2 - | 4,2 - 2x | = 0

| 4,2 - 2x | = 0,2 - 0

| 4,2 - 2x| = 0,2 

=> 4,2 - 2x = 0,2 hoặc 4,2 - 2x = -0,2

+> 4,2 - 2x = 0,2

             2x = 4,2 - 0,2

             2x = 4

              x = 4:2

              x = 2

+> 4,2 -2x = -0,2

2x = 4,2+ 0,2

2x = 4,4

x= 4,4 :2

x = 2,2 

0,2 - | 4,2 - 2x | = 0

        | 4,2 - 2x | = 0,2 - 0

        | 4,2 - 2x | =  0,2

=>  4,2 - 2x = \(\pm\)0,2

+) 4,2 - 2x = 0,2                                   +) 4,2 - 2x = - 0,2 

             2x = 4,2 - 0,2                                         2x = 4,2 - (- 0,2 )

             2x = 4                                                     2x = 4,4

             x = 4:2 =2                                                 x = 4,4:2 = 2,2

Vậy x \(\in\){ 2; 2,2}

a, \(4.3^{2x}-2.9^x-54=0\)

\(\Rightarrow3^{2x}\left(4-2\right)=54\)

\(\Rightarrow3^{2x}=27=3^3\)

Vì \(3\ne\pm1;3\ne0\) nên \(2x=3\Rightarrow x=\dfrac{3}{2}\)

b, \(\dfrac{1}{2}.2^x+4.2^x-288=0\)

\(\Rightarrow2^x\left(\dfrac{1}{2}+4\right)=288\)

\(\Rightarrow2^x=64=2^6\)

Vì \(2\ne\pm1;2\ne0\) nên \(x=6\)

(x-1)²=25

=>x-1=-5 hoặc x-1=5

=>x=-4 hoặc x=6

2x-1=5

2x=5+1=6

x=6:2

x=3

0,2-4,2-2x=0

-4-2x=0

2x=-4-0=-4

x=-4:2

x=-2

(x - 1)² = 25

(x - 1)² = 5²

Suy ra x - 1 = 5

                x = 5 + 1

                x = 6. Vậy x = 6

2x - 1 = 5

     2x = 5 + 1

      2x = 6

       x = 6 : 2

       x = 3. Vậy x = 3

0,2 - 4,2 - 2x = 0

   -4        - 2x = 0

                 2x = -4 - 0

                 2x = -4

                  x = -4 : 2

                  x = -2. Vậy x = -2 

a) \(\Rightarrow\left[\begin{array}{nghiempt}2x-1=5\\2x-1=-5\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=3\\x=-3\end{array}\right.\)

Vậy: \(x=3\) hoặc \(x=-3\)

b) \(\Rightarrow\left[\begin{array}{nghiempt}x+\frac{3}{4}=3\\x+\frac{3}{4}=-3\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{9}{4}\\x=-\frac{15}{4}\end{array}\right.\)

Vậy: \(x=\frac{9}{4}\) hoặc \(x=-\frac{15}{4}\)

c) \(\Rightarrow\left[\begin{array}{nghiempt}4,2-2x=0,2\\4,2-2x=-0,2\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=2\\x=\frac{11}{5}\end{array}\right.\)

Vậy: \(x=2\) hoặc \(x=\frac{11}{5}\)

\(\text{1,(-14)+(2x–4^2)=/-10/×/5/}\)

\(-14-16+2x=10.5\)

\(-30+2x=50\)

\(2x=50--30\)

\(2x=80\)

\(x=80:2\)

\(x=40\)

\(\text{2,(-100)–/x+20/=-150}\)

\(|x+20|=-100--150\)

\(|x+20|=50\)

\(\Rightarrow\orbr{\begin{cases}x+20=50\\x+20=-50\end{cases}\Leftrightarrow\orbr{\begin{cases}x=30\\x=-70\end{cases}}}\)

\(\Rightarrow x\in\left\{-70;30\right\}\)

\(\text{3)3x+16=4x–61}\)

\(3x-4x=-61-16\)

\(-x=-77\)

\(\Rightarrow x=77\)

\(\text{4,2(x–5)–3(x+6)=0}\)

\(2x-10-3x-18=0\)

\(2x-3x=0+18+10\)

\(-x=28\)

\(x=-28\)

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