Răspuns:
Explicație pas cu pas:
1. 2+x=x² x²-x-2=0 (x+1)(x-2)=0 x1=-1 x2=2
4. x-5=4 x=9
7. 7-x=1 x-7-1=6
8.x²-25=144 x²=144+25=169 x1,2=±13
9. 2x+3=x² x²-2x-3=0 x1,2=1±√1+3 x1=-1 x2=3
10. x+1=x²-2x+1 x²-3x=0 x1=0 x2=3
12. 169-x²=144 x²=169-144=25 x=±5
14 √(x-1)=2 x-1=4 x=5 x>1
