3x(2x-5)=2(x^2+2) спс

3x( 2x - 5 ) = 2( x^2 + 2 )
6x^2 - 15x = 2x^2 + 4
4x^2 - 15x - 4 = 0
4( x^2 - 3,75x - 1 ) = 0
D = 14,0625 + 4 = 18,0625 = 4,25^2
X1 = ( 3,75 + 4,25 ) : 2 = 4
X2 = ( 3,75 - 4,25 ) : 2 = - 0,25

6x^2-15x=2x^2+4
6x^2-2x^2-15x-4=0
4x^2-15x-4=0
D=15^2-4*4*(-4)=289=17^2
x=(15+-17)/(2*4)
x1=-0,25
x2=4