Răspunsuri

2014-04-12T12:57:34+03:00
2x-x²-6+3x-(5x+x²-25-5x)=-2x²+12x-5x+5
5x-x²-6-x²+25=-2x²+7x+5
-2x²+5x+19=-2x²+7x+5   se simplifica -2x²
5x-7x=5-19
-2x=-14
2x=14
x=7
2014-04-12T12:57:35+03:00