7a²-2a-3=7(a-(1-√22)/7)(a-(1+√22)/7)=1/7(a-1+√22)(a-1-√22)
D=4+84=88
a1=(2-2√22)/14=(1-√22)/7
a2=(1+√22)/7
7a²-6a-1=7(a+1/7)(a-1)=(7a+1)(a-1)
D=36+28=64
a1=(6-8)/14=-1/7
a2=(6+8)/14=1
(7a²-2a-3)/(7a²-6a-1)=((a-1+√22)(a-1-√22)/[7(7a+1)(a-1)]
(5500-3500)/50=40 автомобилей
А(х-у)+3(х-у)/(а-3)(а+3)=(х-у)(а+3)/(а+3)(а-3)=х-у/а-3 5,8-3,4/3,1-3=2,4/0,1
√2соs4πx=-1
cos4πx=-1|√2 или√2/2
4πx=(плюс минус) π/4+2πn( делим на 1/4π)
x=(плюс минус)1/8+1/2n