Question

Решить систему x + y = 3 
x^2+y^2= 29

Answer 1

$left { {{x + y=3} atop {x^2 + y^2 =29}} right.$
$x^{2} + (3-x)^2 = 29$
$x^{2} + 9-6x +x^2 = 29$
$2x^{2}-6x-20 = 0$
D = 196
x1 =  5
x2 = -2

y1 = -2
y2 = 5