x^2 + y^2 = 25,
x + y = 7
y = 7 - x
x^2 + (7 - x)^2 = 25
x^2 + 49 - 14x + x^2 = 25
2x^2 - 14x + 24 = 0
D = 14 * 14 - 4 * 2 * 24 = 196 - 192 = 4 = 2^2
x1,2 = (14 ± 2)/2 * 2
x1 = 4
x2 = 3
Ответ: x1 = 4; x2 = 3.
x^2 + y^2 = 25,
x + y = 7
y = 7 - x
x^2 + (7 - x)^2 = 25
x^2 + 49 - 14x + x^2 = 25
2x^2 - 14x + 24 = 0
D = 14 * 14 - 4 * 2 * 24 = 196 - 192 = 4 = 2^2
x1,2 = (14 ± 2)/2 * 2
x1 = 4
x2 = 3
Ответ: x1 = 4; x2 = 3.