Question

Найдите сумму и произведение корней уравнения: X^2-6x+8=0 X^2-5x+6=0 X^2+2x-3=0 X^2-7x+2=0 X^2-6x+5=0 X^2-x-30=0

Answer 1

X^2 - 6x + 8  =0
D = 36-4*8=4
x1= 8 /2 = 4
x2= 4/2 = 2
X1+x2 = 6
x1*x2 = 8

X^2-5x+6=0
D= 25 - 4*6=1
x1= 6/2 = 3
x2= 4/2 = 2
x1+x2=5
x1*x2=6

X^2+2x-3=0
D=4 - 4*(-3) = 16
x1= -2+4/2 = 1
x2= -2-4/2 = -3
x1+x2= -2
x1*x2=-3

X^2-7x+2=0
по теореме Виета
x1+x2 = -b/a = 7
x1*x2 = с/a =2

X^2-6x+5=0
D= 16
x1=1
x2=5
x1+x2=6
x1*x2=5

X^2-x-30=0
D=121
x1=-5
x2=6
x1+x2=1
x1*x2=-30