Question

Система квадратных уравнений
А)х²+6хy+8y²=91
x+3y-10=0

Answer 1

{х²+6хy+8y²=91
{x+3y-10=0 ⇒x=10-3y
(10-3y)²+6y(10-3y)+8y²-91=0
100-60y+9y²+60y-18y²+8y²-91=0
9-y²=0
y²=9
y1=-3 ⇒x1=10-3*(-3)=19
y2=3⇒x2=10-3*3=1
(19;-3);(1;3)