Răspunsuri

2014-09-22T16:35:32+03:00
(x-5)(x+5)-(x-3)²=x-9
x²-5²-x²-2·3x+3²=x-9
-6x-x=-9+5+2-9
-7x=-11
x=-11/-7
x=1  -4/7