\(a,210-5\left(x-11\right)=200\\ \Rightarrow5\left(x-11\right)=10\\ \Rightarrow x-11=2\\ \Rightarrow x=13.\\ b,\left(2x+1\right):7=2^2+3^2\\ \Rightarrow\left(2x+1\right):7=4+9\\ \Rightarrow\left(2x+1\right):7=13\\ \Rightarrow2x+1=91\\ \Rightarrow2x=90\\ \Rightarrow x=45.\\ c,450:\left[41-\left(2x-5\right)\right]=3^2.5\\ \Rightarrow450:\left[41-\left(2x-5\right)\right]=45\\ \Rightarrow41-\left(2x-5\right)=10\\ \Rightarrow2x-5=31\\ \Rightarrow2x=36\\ \Rightarrow x=18.\\ d,\left(5x-9\right).7+3=80\\ \Rightarrow\left(5x-9\right).7=77\\ \Rightarrow5x-9=11\\ \Rightarrow5x=20\\ \Rightarrow x=4.\)

a) \(210-5\left(x-11\right)=200\)

\(5.\left(x-11\right)=210-200\)

\(5.\left(x-11\right)=10\)

\(x-11=10:5\)

\(x-11=2\)

\(x=2+11\)

\(x=13\)

b) \(\left(2x+1\right):7=2^2+3^2\)

\(\left(2x+1\right):7=13\)

\(2x+1=13.7\)

\(2x=91-1\)

\(2x=90\)

\(x=90:2\)

\(x=45\)

c) \(450:\left[41-\left(2x-5\right)\right]=3^2.5\)

\(450:\left[41-\left(2x-5\right)\right]=45\)

\(\left[41-\left(2x-5\right)\right]=450:45\)

\(\left[41-\left(2x-5\right)\right]=10\)

\(2x-5=41-10\)

\(2x-5=31\)

\(2x=31+5\)

\(2x=36\)

\(x=36:2\)

\(x=18\)

d) \(\left(5x-9\right).7+3=80\)

\(\left(5x-9\right).7=80-3\)

\(5x-9=77:7\)

\(5x-9=11\)

\(5x=11+9\)

\(5x=20\)

\(x=20:5\)

\(x=4\)

a, 36:(x–5) =  2 2

(x–5) = 9

x = 14

b, [3.(70–x)+5]:2 = 46

[3.(70–x)+5] = 92

70–x = 29

x = 41

c, 450:[41–(2x–5)] =  3 2 .5

41–(2x–5) = 10

2x–5 = 31

2x = 36

x = 18

d, 230+[ 2 4 +(x–5)] = 315. 2018 0

16+(x–5) = 315–230

x–5 = 85–16

x = 69+5

x = 74

e,  2 x + 2 x + 1  = 48

2 x .(2+1) = 48

2 x = 16 =  2 4

x = 4

f,  3 x + 2 + 3 x  = 2430

3 x . 3 2 + 1 = 2430

3 x = 2430:10 = 243 =  3 5

x = 5

a) x = 2.               

b) x = 7.

c) x= 12.

d)  x= 45.

e) x = 18.

f) x  = 10.

a: \(\Leftrightarrow-\dfrac{450}{-115-15\left(2x-1\right)^2}=8\cdot5-37=3\)

\(\Leftrightarrow\dfrac{450}{115+15\left(2x-1\right)^2}=3\)

\(\Leftrightarrow115+15\left(2x-1\right)^2=150\)

=>15(2x-1)²=35

=>(2x-1)²=7/3

hay \(x\in\left\{\dfrac{3+\sqrt{21}}{6};\dfrac{3-\sqrt{21}}{6}\right\}\)

\(450:\left[41-\left(2x-5\right)\right]=3^2\cdot5\\ \Rightarrow41-\left(2x-5\right)=450:45=10\\ \Rightarrow2x-5=41-10=31\\ \Rightarrow2x=36\\ \Rightarrow x=18\)

\(450:\left[41-\left(2x-5\right)\right]=3^2.5\)

\(\Leftrightarrow450:\left(41-2x+5\right)=45\)

\(\Leftrightarrow46-2x=10\)

\(\Leftrightarrow2x=36\Leftrightarrow x=18\)

\(450:\left[41-\left(2x+5\right)\right]=3^2.5\)

\(\Leftrightarrow41-2x-5=12,5\)

\(\Leftrightarrow-2x=-23,5\)

\(\Leftrightarrow x=\dfrac{47}{4}\)

`450 : [41 - (2x+5)] = 3^2 .5`

`=> 450 : (41 - 2x-5) = 9.5`

`=> 450 : (36 - 2x) = 45`

`=> 36-2x= 450:45`

`=>36-2x=10`

`=> 2x= 26`

`=> x= 13`

Vậy `x= 13`