Răspunsuri

2014-11-08T10:10:38+02:00
7x-35+63-5x+4=9×+18-21x
7x+28-5x+4=9x+18-21x
7x-5x+32=9x+18-21x
2x+32=9x+18-21x
2x+32=-12x+18
2x+32+12x=18
14x+32=18
14x=18-32
14x=-4
x=-14:14
x=-1