16 - 64x² = 0 5x²+2 = 4 x² = 30 - x
-64x² = 0 - 16 5x²=4-2 x² - 30 + x = 0
-64x² = -16 5x²=2 x² + x - 30 = 0 (a=1; b=1; c=-30)
x² = 16/64 x = √2/5 D = b²-4ac
x = -4/8 x = -√2/5 D = 1+120 = 121 (√121=11)
x = 4/8. x1 = -b+√D/2a = -1+11/2 = 10/2 = 5.
x2 = -b-√D/2a = -1-11/2 = -12/2 = -6.
4+9x²-12x = 0 5x²+12 = 16x
9x²-12x + 4 = 0 (a=9;b=-12;c=4) 5x² -16x +12 = 0 (a=5;b=-16;c=12)
D = b²-4ac D = b²-4ac
D = 144 -144 = 0 D = 256 -240 = 16 (√16=4)
xо = -b/2a = -(-12)/18 = 2/3. x1=-b+√D/2a = -(-16)+4/10 = 20/10 = 2.
x2 = -b-√D/2a = -(-16)-4/10 = 12/10 =1,2.
1+5x²+x=0
5x²+x+1 = 0 (a=5;b=1;c=1)
D = b²-4ac
D = -19
D < 0
Ответ: нет корней