Secx=1/cosx cosecx=1/sinx
(sinx/cosx:1/cosx)²+(cosx/sinx:1/sinx)²-cos²x=sin²x+cos²x-cos²x=sin²x
А) (8а+3a)(4-a)= 11a(2-a) = 22a -11a^2
б) 5x(x-1)-3x(4-x)= 5x^2 - 5x -12x+3x^2 = 8x^2 -17x
в) 2a(7b-a)+3b(b-5a) = 14ab - 2a^2 +3b^2 -15ab = 3b^2 - 2a^2 -ab
г) 4* p^2 * q^2 -p(7p*q^2 +p -q) +2q(p^2 q -p) = 4p²q² -7p²q² - p² +pq +2p²q² -2pq = -pq-p²-p²q²
Сума: 9+18+27+36+45+54+63+72+81+90+99+108+117=819