Question

Tìm số tự nhiên x biết: 3².(x+4)−5²=5.2² 
Vậy x =

Answer 1

\(3^2.\left(x+4\right)-5^2=5.2^2\)

= \(9.\left(x+4\right)-25=5.4\)

= \(9.\left(x+4\right)-25=20\)

= \(9.\left(x+4\right)=20+25\)

= \(9.\left(x+4\right)=45\)

\(\left(x+4\right)=45:9\)

\(x+4=5\)

\(x=5-4\)

\(x=1\)

Answer 2

3².(x+4)-5²=5.2²

3².(x+4)=5²+(5.2²)

3².(x+4)=45

x+4=45:3²

x+4=5

x=5-4

x=1

Answer 3

3^2 x (X+4)-5^2=5x2^2

  9   x (X+4)-25 = 20

  9   x  (X+4)     =  20+25 = 45

          X+4        = 45 : 9 = 5

                  X    =  5-4 

                 X     = 1

                        Vậy X= 1

Answer 4

3².(x + 4) - 5² = 5.2²

9.(x + 4) - 25 = 20

9.(x + 4) = 20 + 25

9.(x + 4) = 45

x + 4 = 45 : 9

x + 4 = 5

x = 5 - 4

x = 1

Answer 5

3^2.(x+4)-5^2=5.2^2

9.(x+4)-25=20

9.(x+4)    =20+25

9.(x+4)    =45

   x+4      =45:9

   x+4      =5

   x          =5-4

   x          =1