Tìm x,y thuộc N,biết:

a,1440:[41-(2x-5)]=2⁴*3

1440:[41-(2x-5)]=48

41-(2x-5)=1440:48

41-(2x-5)=30

2x-5=11

2x=16

x=8

5*[15²-(x-10)]5³=0

5*[15²-(x-10)]=0:5^3

5*[15²-(x-10)]=0

15²-(x-10)=0:5

15²-(x-10)=0

x-10=225-0

x-10=225

x=235

a) đặt [41-(2x-5)] là a <=> 1440 : a = 48
=> a = 30 <=> [41-(2x-5)] = 30   => 41-(2x-5) =30
<=> -(2x-5) = -11 <=> 2x-5 = 11 <=> 2x = 16 <=> x=2

b) tương tự câu a
gợi ý đáp án : x = 210

1440:[41-(2x-5)]=2⁴.3

1440 : [41 - (2x - 5 ) ] = 48

41 - (2x - 5 ) = 1440 : 48

41 - ( 2x - 5 ) = 30

2x - 5 = 41 - 30

2x - 5 = 11

2x = 11 + 5

2x = 16

x= 16 : 2

x = 8

a ) \(\left(19x+2,5^2\right)\div14=\left(13-8\right)^2-4^2\)

\(\Rightarrow\left(19x+50\right)\div14=5^2-16\)

\(\Rightarrow\left(19+50\right)\div14=25-16=9\)

\(\Rightarrow19x+50=9\times14\)

\(\Rightarrow19x+50=126\)

\(\Rightarrow19x=126-50\)

\(\Rightarrow19x=76\)

\(\Rightarrow x=4\)

b ) \(1440\div\left[41-\left(2x-5\right)\right]=2^4.3\)

\(\Leftrightarrow1440\div\left[41-\left(2x-5\right)\right]=48\)

\(\Leftrightarrow41-\left(2x-5\right)=30\)

\(\Leftrightarrow2x-5=11\)

\(\Leftrightarrow2x=16\)

\(\Leftrightarrow x=8\)

\(1440:\left[41-\left(2x-5\right)\right]=2^4.3\)

\(\Rightarrow1440:\left[41-\left(2x-5\right)\right]=48\)

\(\Rightarrow41-\left(2x-5\right)=30\)

\(\Rightarrow2x-5=11\)

\(\Rightarrow2x=16\)

\(\Rightarrow x=8\)

Vậy \(x=8\)

\(1440:\left[41-\left(2x-5\right)\right]=2^4\cdot3\)

\(1440:\left[41-\left(2x-5\right)\right]=48\)

\(41-\left(2x-5\right)=\frac{1440}{48}=30\)

\(2x-5=41-30=11\)

\(2x=16\)

\(x=8\)

t) \(1440:\left[41-\left(2x-5\right)\right]=2^4.3\)

\(1440:\left[41-\left(2x-5\right)\right]=16.3\)

\(1440:\left[41-\left(2x-5\right)\right]=48\)

\(41-\left(2x-5\right)=1440:48\)

\(41-\left(2x-5\right)=30\)

\(2x-5=41-30\)

\(2x-5=11\)

\(2x\) \(=11+5\)

\(2x\) \(=16\)

\(x=16:2\)

\(x=8\)

Vậy \(x=8\)

\(\frac{1440}{41-\left(x-5\right)}=2^4.3\)

\(\Rightarrow\left[41-\left(x-5\right)\right]2^4.3=1440\)

\(\Rightarrow\left[41-\left(x-5\right)\right].48=1440\)

\(\Rightarrow41-\left(x-5\right)=30\)

\(\Rightarrow x-5=11\)

\(\Rightarrow x=16\)

Vậy \(x=16\)

1e) Để \(\frac{2x-1}{x-3}\) nguyên thì \(2x-1⋮x-3\)

\(\Leftrightarrow2x-6+5⋮x-3\)

\(\Leftrightarrow2\left(x-3\right)+5⋮x-3\)

Do \(2\left(x-3\right)⋮x-3\) \(\Rightarrow5⋮x-3\)

\(\Rightarrow x-3\in\left\{-5;-1;1;5\right\}\)

\(\Leftrightarrow x\in\left\{-2;2;4;8\right\}\)

Vậy:...................

a) 1440: [41-{2x-5}]=16.3

    41-(2x-5)=1440-48

   41-(2x-5)=1392

     2x-5=41-1392

     2x-5=-1351

        2x=-1351+5

        2x=-1346

         x=(-1346):2

         x=-673

b) 5.[225-(x-10)]-125=0

      5.[225-(x-10)=0+125

          225-(x-10)=125:5

          225-(x-10)=25

                x-10=225-25

               x-10=200

               x=200+10

             x=210

c) x thuộc {1,2,3,6}