42х⁵/у⁴ * у²/14х³=3х² / у²
63а³в / с : (18а²в)=(63а³в) / (18а²вс)=7а/2с
(4а²-1)/(а²-9) : (6а+3)/(а+3)=((2а+1)(2а-1)) / ((а-3)(а+3)) * (а+3)/(3(2а+1))=(2а-1)/(3(а-3))
(p-q)/p *( p/(p-q) +p/q )=(p-q) /p * (pq+p²-pq)/(q(p-q))=p²/pq=p/q
По теореме Виета:
x^2+px+q=0
х1+х2=-p=7
p=-7
х1×х2=q=-8
q=-8
x^2-7x-8=0
D = 16 + 84 = 100 ; √ D = 10
X1 = ( 4 + 10) : 2 = 7
X2 = ( 4 - 10 ) : 2 = - 3