Question

(3x+4)(x-10)+(10-x)(x-8)=0

Answer 1

(3x+4)(x-10)+(10-x)(x-8)=0
3x²-30x+4x-40+10x-80-x²+8x=0
2x²-8x-120=0
x²-4x-60=0, D=16+240=256,√D=√256=16
x1=(4+16)/2=20/2=10, x1=10
x2=(4-16)/2=-12/2=-6, x2=-6

Answer 2

(3х+4)*(х-10)+(10-х)*(х-8)=0
3х²-30х+4х-40+10х-80-х²+8х=0
2х²-8х-120=0
 D=(-8)²-4*2*(-120)=64+960=1024=32²
Х1=8-322*2=-244=-6
Х2=8+322*2=404=10
проверка
(3*(-6)+4)(-6-10)+(10-(-6))*(-6-8)=0
-14*(-16)+16*(-14)=0
14-14=0
0=0
(3*10+4)(10-10)+(10-10)(10-8)=0
0=0