Question

a) 5x - 7x - 16 = 224

b) 2^x + 2^y = 24  (x,y \(\varepsilon\)N / x < y)

Answer 1

a) 5x - 7x - 16 = 224

 5x - 7x = 224 + 16

 5x - 7x = 240

 x( 5 - 7) = 240

 x . (-2) = 240

 Suy ra x = -120

b) 2^x + 2^y = 24 

  2^x + 2^y = 8 + 16

Suy ra x = 3 ; y = 4

Answer 2

a) 5x - 7x - 16 = 224

    ( 5 - 7 ) x -16 = 224

       - 2 x - 16 = 224

          - 2x = 224 + 16

          - 2x = 240

              x  = 240 : ( - 2)

              x  = 240 x 2

              x  = 480

b      -.- I don't know