sin(84)-sin(60)-cos(60)-cos6=sin(90-6)-sqrt(3)/2-1/2-cos6=-(sqrt(3)+1)/2
5x² - 8xy - 13y² = 5x² - 13xy + 5xy - 13y² = x(5x -13y) + y(5x - 13y) =
= (x + y)(5x - 13y);
b1=5/2^1=5/2
b2=5/2²=5/4
q=(5/4)/(5/2)=1/2
Решение на фотографии