(3х-4)(х+2)=(х-3)^2-19

Question

(3х-4)(х+2)=(х-3)^2-19

Answer 1

(3х-4)(х+2)=(х-3)²-19
3х²+6х-4х-8 =  х²-6х+9-19
3х²+2x+6х-х²=9-19+8
2х²+8х=-2
2х²+8х+2=0
х²+4х+1=0
D=4*4 - 4*1*1= 16-4=12
x1= (-4+√12)/2 = -2+√3
x2=-2-√3

Comments

так как-то