a,10x+65=125

   10x      =125-65

       x      =60:10

       x      =6

Vậy:...

b,45-(5-2x)^3=2.3^2

   45-(5-2x)^3=18

    (5-2x)^3    =45-18

    (5-2x)^3    =27=3^3

=> 5-2x  = 3

     2x = 5-3

     x= 2:2

     x=1

Vậy:....

-Hok tốt ~ K mk nhak.

a, 10x + 65 = 125

10x = 125 - 65

10x = 60

x = 60 : 10

x = 6

b,45-(5-2x)^3=2.3^2

45 - ( 5 - 2x )^3 =18

(5 - 2x)^3 = 45 - 18

(5 - 2x )^3= 3^3

5 - 2x = 3

2x = 2

x = 1

c,2(x-3)-12=(-10)

2x - 6 -12 =-10

2x = -10 + 6 + 12

2x = 8

x = 4

d,x-12=(-13)+1+|-13|

x - 12 = -13 + 1 + 13

x - 12 = 1

x = 13

hok tốt!!!

\(\text{a)}\)\(10x+65=125\)

\(\Rightarrow10x=60\)

\(\Rightarrow x=6\)

\(b\text{)}\)\(45-\left(5-2x\right)^3=2.3^2\)

\(\Rightarrow45-\left(5-2x\right)^3=18\)

\(\Rightarrow\left(5-2x\right)^3=45-18\)

\(\Rightarrow\left(5-2x\right)^3=27\)

\(\Rightarrow\left(5-2x\right)^3=3^3\)

\(\Rightarrow5-2x=3\)

\(\Rightarrow2x=2\Rightarrow x=1\)

10x+65=125

10x=125-65

10x=60

x=60:10

x=6

a) \(75:\left(x-2\right)+4=7\)

\(\Rightarrow75:\left(x-2\right)=7-4\)

\(\Rightarrow75:\left(x-2\right)=3\)

\(\Rightarrow x-2=75:3\)

\(\Rightarrow x-2=25\)

\(\Rightarrow x=27\)

b) \(125-3\left(x+3\right)=65\)

\(\Rightarrow3\left(x+3\right)=125-65\)

\(\Rightarrow3\left(x+3\right)=60\)

\(\Rightarrow x+3=60:3\)

\(\Rightarrow x+3=20\)

\(\Rightarrow x=17\)

a,\(75:\left(x-2\right)+4=7\\ \Rightarrow75:\left(x+2\right)=3\\ \Rightarrow x+2=25\\ \Rightarrow x=23.\)

b, \(125-3\left(x+3\right)=65\\ \Rightarrow3\left(x+3\right)=60\\ \Rightarrow x+3=20\\ \Rightarrow x=17.\)

a, x= 27

b, x= 17

a)15+5x=40 b)10x+65=125

5x=40-15 10x =125-65

5x=25 10x =60

x=25:5 x =60:10

X=5 x =6

b)25+3(x-8)=106 d)4(x+41)=400

3(x-8)=106-25 x+41=400:4

3(x-8)= 81 x+41 =100

x-8=81:3 x =100-41

x-8=27 x =59

x =27+8

x =35

Chúc bạn học giỏi nhé!

à phần c và d là

c)25+3(x-8)=106 d)4(x+41)=400

3(x-8)=106-25 x+41=400:4

3(x-8)= 81 x+41 =100

x-8=81:3 x =100-41

x-8=27 x =59

x =27+8

ó x =35

Cảm ơn nhé!

a)125-3.(x+3)=65

3 .(x + 3) = 125 - 65

3. (x + 3) = 60

x + 3 = 60 : 3

x+3 = 20

x = 20-3

x=17

 b) 8.2^x = 128

2^x = 128 : 8 

2^x = 16

2^x = 2⁴

=> x = 4 

thanks bạn !!!!!!

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THANKS

Bạn sử dụng bất đẳng thức \(|a|+|b\ge|a+b|\) nhé

\(\left|125-x\right|+\left|x-65\right|\)

Ta có: \(\hept{\begin{cases}\left|125-x\right|\ge125-x\forall x\\\left|x-65\right|\ge x-65\forall x\end{cases}\Rightarrow}\left|125-x\right|+\left|x-65\right|\ge125-x+x-65=60\)

Dấu ' = ' xảy ra \(\Leftrightarrow\hept{\begin{cases}\left|125-x\right|=125-x\\\left|x-65\right|=x-65\end{cases}}\Leftrightarrow\hept{\begin{cases}125-x\ge0\\x-65\ge0\end{cases}\Leftrightarrow\hept{\begin{cases}x\le125\\x\ge65\end{cases}\Rightarrow65\le}x\le125}\)

Vậy GTNN của \(\left|125-x\right|+\left|x-65\right|=60\Leftrightarrow65\le x\le125\)

Tham khảo nhé~