Question

Rezolvati ecuatiile: a)x^2=1 b)2x^2+1=-7 c)x^2+2x^2=4x^2

Answer 1

a)$x^{2}$ = 1
   x = $\sqrt{1}$
   x = 1
b)2$x^{2}$+1 = -7
   2$x^{2}$ = -7-1
   2$x^{2}$ = -8
   $x^{2}$ = $\frac{-8}{2}$
   $x^{2}$ = -4 ·/(-1)
   -x = $\sqrt{4}$ 
   -x = 2 ·/(-1)
    x = -2
c)$x^{2}$+2$x^{2}$=4$x^{2}$
   3$x^{2}$ ≠ 4$x^{2}$
   Ecuatia nu are solutie.