D=4-4*1*(-48) = 4+192 =196
x1=(-2+14)/2*2 = 12/4=3
x2=(-2-14)/2*2 = -16/4=-4
(-4;3)
(X2 + 3x)/2=(x+7)/4
2*x*x + 6x=x + 7
2*x*x + 5*x - 7 =0
D= 25+56=81
X1=(-6+9)/4 X1=0,75
X2=(-6-9)/4 X1=-3,75