Question

x^2-3x-4=0 по теорема виетта

Answer 1

x1+x2=3=x1=-1
x1•x2=-4=x2=4

Answer 2

X1+X2=3
X1*X2=-4
X1=3-x2

(3-x2)*x2=-4
X2^2-3x2-4=0
D=25
X2=-1 X1=4
x2=4. X1=-1
(-1;4)(4;-1)