652-655

652

x*(10*x)=21

10x-x2=21

10x-x2-21=0

-x2+10x-21=0

x2-10+21=0

D=100-84=16

x1=10+√16/2=7

x2=10-√16/2=3

x1+x2=10

x1*x2=21

x2-10x+21=0

653

x*(14-x)=36,75

14x-x2=36,75

14x-x2-36,75=0

-x2+14x-36,75=0

x2-14x+36,75=0

D=196-147=49

x1=14+√49/2=10,5

x2=10-√49/2=1,5

x1+x2=10,5

x1*x2=1,5

x2-10,5x+1,5=0

641

ա․

x1=1

x2=5

x1+x2=6

x1*x2=5

x2-6x+5=0

x1=1

x2=5

(x-1)(x-5)=0

x2-5x-x+5=0

x2-6x+5=0

բ․

x1=-2

x2=3

x1+x2=1

x1*x2=-6

x2-x-6=0

x1=-2

x2=3

(x+2)(x-3)=0

x2-3x+2x-5=0

x2-x-5=0

գ․

x1=4

x2=6

x1+x2=10

x1*x2=24

x2-10x+24=0

դ․

x1=-3

x2=-6

x1+x2=-9

x1*x2=18

x2+9x+18=0

ե․

x1=0,5

x2=4

x1+x2=4,5

x1*x2=2

x2-4,5x+2=0

զ․

x1=1,2

x2=-5

x1+x2=-3,8

x1*x2=-6

x2+3,8x-6=0

է․

x1=1

x2=-1

x1+x2=0

x1*x2=-1

x2-1=0

ը․

x1=5

x2=5

x1+x2=10

x1*x2=25

x2-10x+25=0