1)0.6x+9x^2=0
2)0.5x^2-1=0
3)x^2+9x=0
4)x^2+7x+12=0
5)x^2-2x-35=0
6)3x^2-8x+5=0
7)2x^2-5x-3=0
8)x^4-4x^2+4=0
9)x^4+10x^2+25=0
10)2x^4-9x^2+4=0
1) 0.6x+9x²=0
0.6x(1+15x)=0
0.6х=0 или 1 + 15х = 0
х = 0 х = -1/15
Ответ. х = -1/15, х = 0
2) 0.5x²-1=0
0.5x²=1
x²=2
х = ±√2
Ответ. х = ±√2
3) x²+9x=0
x(х+9)=0
х = 0 или х+9 = 0
х = -9
Ответ. х = 0, х = -9
4) x²+7x+12=0
Д = 49 - 48 = 1
х1 = (-7-1)/2 = -4
х2 = (-7+1)/2 = -3
Ответ. х = -4, х = -3
5) x²-2x-35=0
Д = 4 + 140=144
х1 = (2-12)/2 = -5
х2 = (2+12)/2 = 7
Ответ. х = -5, х = 7
6) 3x²-8x+5=0
Д = 64 - 60 = 4
х1 = (8-2)/6=1
х2 = (8+2)/6 = 10/6=5/3
Ответ. х = 1, х = 5/3
7) 2x²-5x-3=0
Д = 25 + 24 = 49
х1 = (5 - 7)/4 = -0,5
х2 = (5 + 7)/4 = 3
Ответ. х = -0,5; х = 3
8) x⁴-4x²+4=0 у = х²
(х²- 2)²=0
х²- 2=0
х²= 2
10) 2x⁴-9x²+4=0, у = х²
2у²-9у+4=0
Д = 81 - 32 = 49
у1= (9-7)/4 = 1/4
у2 = (9+7)/4 = 4
х²=1/4 х²=4
х = ±1/2 х=±2
Ответ. х = ±1/2; х=±2