Question

Решите: х^2+12=7х;
1+8х=9х^2 ;
(х-2)^2=3х-8

Answer 1

Ответ:

x^2+12=7x

х^2 +12-7х=0

х^2 - 7х+12=0

D=49-4*12=49-48=1

х1=(7+1)/2=8:2=4

х2=(7-1)/2=6:2=3.

1+8х=9х^2

8х+1=9х^2

-9x^2+8x+1=0| *(-1)

D = (-8)² - 4 * 9 * (-1) = 64 + 36 = 100

х1 = 8 + 10 /18 = 1

х2 = 8 - 10 / 18 = -2 / 18 = -1/9

(х-2)^2=3х-8

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

x^2-7x+12=0

D=49-48=1

x1=(7+1)/2=4

x2=(7-1)/2=3