a: \(280-\left(x-140\right):35=270\)

=>(x-140):35=280-270=10

=>x-140=350

=>x=350+140

=>x=490

b: \(\left(190-2x\right):35-32=16\)

=>\(\left(190-2x\right):35=32+16=48\)

=>\(190-2x=35\cdot48=1680\)

=>2x=190-1680=-1490

=>x=-745

c: \(720:\left\lbrack41-\left(2x-5\right)\right\rbrack=2^3\cdot5\)

=>\(720:\left\lbrack41-\left(2x-5\right)\right\rbrack=8\cdot5=40\)

=>41-(2x-5)=720:40=18

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

=>2x=28

=>x=14

d: \(\left(x:23+45\right)\cdot37-22=2^4\cdot105\)

=>\(\left(\frac{x}{23}+45\right)\cdot37=16\cdot105+22=1702\)

=>\(\frac{x}{23}+45=46\)

=>\(\frac{x}{23}=1\)

=>x=23

e: \(\left(3x-4\right)\left(x-1\right)^3=0\)

=>\(\left[\begin{array}{l}3x-4=0\\ x-1=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=\frac43\\ x=1\end{array}\right.\)

f: \(2^{2x-1}:4=8^3\)

=>\(2^{2x-1-2}=2^9\)

=>2x-3=9

=>2x=12

=>x=6

g: \(x^{17}=x\)

=>\(x^{17}-x=0\)

=>\(x\left(x^{16}-1\right)=0\)

=>\(\left[\begin{array}{l}x=0\\ x^{16}-1=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=0\\ x^{16}=1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=0\\ x=1\\ x=-1\end{array}\right.\)

h: \(\left(x-5\right)^4=\left(x-5\right)^6\)

=>\(\left(x-5\right)^6-\left(x-5\right)^4=0\)

=>\(\left(x-5\right)^4\cdot\left\lbrack\left(x-5\right)^2-1\right\rbrack=0\)

=>\(\left(x-5\right)^4\cdot\left(x-4\right)\left(x-6\right)=0\)

=>x∈{4;5;6}

i: \(\left(x+2\right)^5=2^{10}\)

=>\(\left(x+2\right)^5=\left(2^2\right)^5=4^5\)

=>x+2=4

=>x=2

k: 1+2+3+...+x=78

=>\(\frac{x\left(x+1\right)}{2}=78\)

=>x(x+1)=156

=>\(x^2+x-156=0\)

=>(x+13)(x-12)=0

=>x=-13(loại) hoặc x=12(nhận)

l: \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)

=>\(3x-16=2\cdot\frac{7^4}{7^3}=2\cdot7=14\)

=>3x=16+14=30

=>\(x=\frac{30}{3}=10\)

n: \(5^{x}:5^2=125\)

=>\(5^{x-2}=5^3\)

=>x-2=3

=>x=5

m: \(\left(x+1\right)^2=\left(x+1\right)^0\)

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

=>\(\left[\begin{array}{l}x+1=1\\ x+1=-1\end{array}\right.\Rightarrow\left[\begin{array}{l}x=0\\ x=-2\end{array}\right.\)

o: Số số hạng của dãy số 2;4;..;52 là:

(52-2):2+1=50:2+1=25+1=26(số)

Tổng của dãy số 2;4;...;52 là:

\(\left(52+2\right)\cdot\frac{26}{2}=54\cdot13=702\)

(2+x)+(4+x)+...+(52+x)=780

=>26x+702=780

=>26x=78

=>x=3

p: \(70=2\cdot5\cdot7;80=2^4\cdot5\)

=>ƯCLN(70;80)=\(2\cdot5=10\)

70⋮x; 80⋮x

=>x∈ƯC(70;80)

=>x∈Ư(10)

mà x>8

nên x=10

q: \(12=2^2\cdot3;25=5^2;30=2\cdot3\cdot5\)

=>BCNN(12;25;30)=\(2^2\cdot3\cdot5^2=300\)

x⋮12; x⋮25; x⋮30

=>x∈BC(12;25;30)

=>x∈B(300)

mà 0<x<500

nên x=300

Bài 1: 
a) 10³⁰ và 2¹⁰⁰
   Ta có: 10³⁰ = (10³)¹⁰ = 1000¹⁰
              2¹⁰⁰ = (2¹⁰)¹⁰ = 1024¹⁰
   Vì 1000¹⁰<1024¹⁰ nên 10³⁰<2¹⁰⁰
   Vậy ...
b) 5⁴⁰ và 620¹⁰
   Ta có: 5⁴⁰= (5⁴)¹⁰ =625¹⁰
   Vì 620¹⁰<625¹⁰ nên 620¹⁰<5⁴⁰
   Vậy...

\(\left(x-1\right)=\left(2x-3\right)^2\)

\(\Leftrightarrow x-1=4x^2-12x+9\)

\(\Leftrightarrow4x^2-13x+10=0\)

\(\Leftrightarrow4x^2-8x-5x+10=0\)

\(\Leftrightarrow4x.\left(x-2\right)-5.\left(x-2\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(4x-5\right)=0\)

\(\Leftrightarrow\hept{\begin{cases}x-2=0\\4x-5=0\end{cases}}\Leftrightarrow\hept{\begin{cases}x=2\\x=\frac{5}{4}\end{cases}}\)

Vậy: \(x=2\)hoặc \(x=\frac{5}{4}\)(Nếu đúng thì click cho mình nhoa!)

Lâu rồi mình ko giải, sai thì thôi nhé!

a) \(\left(10-2x\right)^2=25-\left(-11\right)\)'=

\(\Leftrightarrow\left(10-2x\right)^2=36\)

\(\Leftrightarrow\left(10-2x\right)^2=6^2\)

\(\Leftrightarrow\orbr{\begin{cases}10-2x=6\\10-2x=-6\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=10-6\\2x=10-\left(-6\right)\end{cases}\Leftrightarrow}\orbr{\begin{cases}2x=4\\2x=16\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=2\\x=8\end{cases}}}\)

Vậy \(x\in\left\{2;8\right\}\)

b) \(-2\left(-x+5\right)-3\left(5-x\right)=4\left(2+x\right)\)

\(\Leftrightarrow-2\left(5-x\right)-3\left(5-x\right)=4\left(2+x\right)\)

\(\Leftrightarrow-5\left(5-x\right)=4\left(2+x\right)\)

\(\Leftrightarrow-25+5x=8+4x\)

\(\Leftrightarrow5x-25=8+4x\)

\(\Leftrightarrow5x=8+4x+25\)

\(\Leftrightarrow5x=4x+33\)

\(\Leftrightarrow5x-4x=33\)

\(\Leftrightarrow1x=33\)

\(\Leftrightarrow x=33\)

Vậy \(x=33\)

a) (10 - 2x)² = 25 - (-11)

(10 - 2x)² = 36

(10 - 2x)² = 6²

=> 10 - 2x = 6

2x = 10 - 6

2x = 4

x =4:2

x=2

Vậy x = 2

b)-2(-x+5) - 3(5 - x) = 4(2+x)

2x - 10 - 15 +3x = 8 + 4x

2x - 25 + 3x = 8 +4x

2x + 3x - 4x = 8 + 25

5x - 4x = 33

x= 33

Vậy x = 33

A) x + 4 = -16

           x = -16 - 4

           x = -20

Vậy x = -20

b) 12- ( x - 5 ) =5.4

     12 -x -5      = 20 

                  x   = 7 - 20 

                  x   = -13

Vậy x= -13

c) (-2)x - ( x - 17 ) = 34 - ( -x + 25 )

    ( -2 )x - x + 17   = 34 + x - 25

            -3x   + 17   = 11 + x

            -3x - x        = 11 - 17

               -4x          =  -6

                        x    = 1,5

Vậy x = 1,5

d) 17x - ( -16x - 37 ) = 2x + 43 

       17x + 16x - 2x   = 43 -37

          30x                 = 6

                  x             = 0,2

Vậy x = 0,2

câu này vừa mk trả lời rùi nè

814 - ( x - 305 ) : 16 = 48 

          ( x - 305 ) : 16 = 814 - 48 

            ( x - 305 ) : 16 = 766 

             ( x - 305 ) = 12256 

               x - 305 = 12561

Sorry mk ko giải đc trong 15 phút đâu , vậy mk thách bạn giải đc trong 5 phút đấy . Nếu bạn giải đc mk xin bạn nhận mk 20 lậy

a)280-(x-140):35=270

         (x-140):35=280-270

         (x-140):35= 10

          x-140     =10x35

          x-140     =350

           x= 350+140

           x=490

b)(190-2x):35-32=16

   (190-2x):35    =16+32

   (190-2x):35    = 48

   190-2x= 48x35

   190-2x=1680

         2x=190-1680

         2x=-1490

          x=-1490:2

          x=-745

c)720:[41-(2x-5)]=\(2^3\)x5

   720:[41-(2x-5)=40

          41-(2x-5)=720:40

          41-(2x-5)=18

               2x-5=41-18

               2x-5=23

               2x=23+5

               2x=28

                x=28:2

                x=14

\(\left(\times:23+45\right)\cdot37-22=2^4\cdot105\)

\(\Rightarrow\times\cdot\frac{37}{23}+1665-22=16\cdot105\)

\(\Rightarrow\times\cdot\frac{37}{23}+1643=1680\)

\(\Rightarrow\times\cdot\frac{37}{23}=1680-1643=37\)

\(\Rightarrow\times=37:\frac{37}{23}=23\)