Question

(х+3)(х+5)= (3х+7)(х+3)                              

Answer 1

x^2+8x+15=3x^2+16x+21

2x^2+8x+6=0

x^2+4x+3=0

(x+1)(x+3)=0

x1=-1

x2=-3

Answer 2

(x+3)(x+5)=(3x+7)(x+3)

x^2+5x+3x+15=3x^2+9x+7x+21

x^2+5x+3x+15-3x^2-9x-7x-21=0

2x^2+8x+6=0

a=2 b=8 c=6

D=b^2*4ac

D=64-48=16

(Корень)D=4

x1,2=-b+-(Kорень)D

x1,2=-8+-44

x1=-1

x2=-3

 

^2 - квадрат