1) 10/(х+3)-8= -х
10/(х+3) - 8+х=0 * (х+3)
10- 8*(х+3) + х(х+3)=0
10-8х-24 + х²+3х=0
х²-5х-14=0
D= 25 - 4*(-14) = 25+56=81
х₁= (5-9)/2= -2
x₂= (5+√81) /2 *1= 14/2=7
Ответ 4) х₁=-2 ; х₂=7
2) 5х+7= 72/(х+1)
(5x+7) (x+1) =72
5x²+5x+7x+7=72
5x²+12x-65=0
D= 144+1300=1444
x₁= (-12+38)/2*5= 26/10= 13/5
x₂= (-12-38)/10= -50/10=-5
Ответ 3)
3) х³-5х²+6х=0
x(x^2-5x+6)=0
x₁=0
x^2 -5x+6=0
D= 25-24=1
x₂=4/2=2
x₃= 6/2=3
Ответ 1)
2/(х-3) = (х+5)/(х²-9)
2(х²-9)=(х-3)(х+5)
2x²-18 = x²+2x-15
2x²-18-x²-2x+15=0
x²-2x-3=0
D= 4+12=16
x₁= (2-4)/2=-1
x₂= 6/2=3
Ответ: х₁=-1 ; х₂=3