X (x-6)+20x2=7X-2 решите уровнение
X(x-6)+20x^2 = 7x - 2 x^2 - 6x + 20x^2 -7x + 2 = 0 21x^2 -13x + 2 = 0 D = (-13)^2 - 4*2*21 = 169 - 168 = 1 √1 = 1 x_1 = (13+1)/42 = 14/42 = 1/3 x_2 = (13-1)/42 = 12/42 = 2/7
2х-6х+20х-7х=-2-2 9х=-4 х=9:(-4) х=-2,25