Question

решите систему методом подстановки
x+y=9
y^2+x=29

Answer 1

-X + Y = 9
Y^2 + X = 29

Y = 9 - X
(9 - X)^2 + X = 29
81 - 18X + X^2 + X - 29
X^2 - 17X + 52 = 0
D = (-17)^2 -4* 1 * 52= 289 - 208 = 81 = 9^2
X1 = 17 + 9 / 2 = 26 / 2 = 13
X2 = 17 - 9 / 2 = 8 / 2 = 4

4 + Y = 9
Y = 5