Question

b,c,d

,помогите))))))

Answer 1

2х +3/х = -7х+21           х≠0
2х²+3= -7х²+21х
9х² - 21х+3=0
3х² -7х+1=0
D=7² - 4*3=37
х1=(7+6,1)/6=2,2
х2=(7-6,1)/6=0,15

с)   ...............................
3(3х+1)-5(2х-1)=7х+3
9х+3-10х+5=7х+3
8х=5
х=5/8

d)   ....................     х≠0,  х≠3
(х+3)(х-3)=х(2х+8)
х²-9=2х²+8х
х²+8х+9=0
D/4=4²-9=7
х1= -4 -2,65= - 6,65
х2= - 4+2,65= - 1,35