решите систему уравнений x+2y=8 x^2-3y=-5

Question

решите систему уравнений

x+2y=8

x^2-3y=-5

Answer 1

x+2y=8

x^2-3y=-5

 

x+2y=8

y=-x/2+4

 

x^2-3y=-5

x^2-3*(-x/2+4)=-5

x^2+1.5x-12+5=0

x^2+1.5x-7=0

D=1.5^2-4*1*(-7)=2.25+28=30.25

x1=(5.5-1.5)/2=4/2=2
x2=(-5.5-1.5)/2=-7/2=-3.5

x+2y=8

 

2+2y=8

-6+2y=0

y=6/2

y1=3

 

-3.5+2y=8

-11.5+2y=0

y=11.5/2

y2=5.75