Question

(x-3)/(x+0.1)=(x-3)/(0.2x+2) указать сумму всех различных действительных корней

Answer 1

(x - 3)(0.2x + 2) = (x + 0.1)(x - 3)
0.2x^2 + 2x - 0.6x - 6 = x^2 - 3x + 0.1x - 0.3
x^2 - 3x + 0.1x - 0.3 - 0.2x^2 - 2x + 0.6x + 6 = 0
0.8x^2 - 4.5x + 5.7 = 0
8x^2 - 45x + 57 = 0
D=201
x1 = (45 - √201)/16
x2 = (45 + √201)/16
x1 + x2 = (45/16) - (√201/16) + (45/16) + (√201/16) = 45*2/16 = 45/8 = 5.625

Ответ: 45/8 = 5,625