Question

Rezolvati in multimea nr naturale urmat ecuatii
a)9*(x-1)-3(x+1)= 2(x+3)-(1+x)
b) (x+1)^2 +x*(x-1)=x^2 + (x+2)*(x-2)+6

Answer 1

a)9(x-1)-3(x+1)= 2(x+3)-(1+x)
   9x - 9 - 3x - 3 = 2x + 6 - 1 - x
   6x - 12 = x + 5
   6x - x = 17
   5x = 17
   => x = 17/5
b) (x+1)^2 +x*(x-1)= x^2 + (x+2)*(x-2)+6
     x^2 + 2x + 1 + x^2 - x = x^2 + x^2 - 4 + 6 
     2x^2 + x + 1 = 2x^2 + 2
     2x^2 - 2x^2 + x = 2-1
     => x = 1