0.1², 0.7², 11², (6/13)², (15/13)²=(1 2/13)², 0.03²
Y=6-4x
x²+18x-12x²-36+48x-16x²-3=0
-27x²+66x-39=0
9x²-22x+13=0
D=484-468=16
x1=(22-4)/18=1⇒y1=6-4*1=6-4=2
x2=(22+4)/18=13/9⇒y2=6-4*13/9=2/9
(1;2) U (13/9;2/9)
7x²-0.35x=0
0.35x(20x-1)=0
x=0 20x-1⇒x=1/20=0.05