Răspunsuri

2014-05-22T18:28:12+03:00
X(x+2)-(x-3)(x+3)=13
x²+2x-x²+9-13=0
2x-4+0
x=4/2=2
2014-05-22T18:32:45+03:00
X la puterea a doua +2x-(x la adoua - 3la a doua)=13
ײ+2x-ײ+3²=13
+x² cu -x² se simplifica si  ne da o 
2x+9=13
2x=13-9
2x=4
x =4 :2
x=2