выполните действие: б) 8/х-2 + х2+2 х+4 в) х-4 у/6 х (х-у) - х+4 у/6 х (х+у) г) b+3/9b-27-b-1/b2-3b

Б

8 / (x-2) + (x²+2x+4) = (8 + (x-2) (x²+2x+4)) / (x-2) = (8+x³-8) / (x-2) = x³ / (x-2)

в

(x-4y) / 6x (x-y) - (x+4y) / 6x (x+y) = [ (x-4y) (x+y) - (x+4y) (x-y) ]/[6x (x²-y²) ]=

= (x²+xy-4xy-4y²-x²+xy-4xy+4y²) / [6x (x²-y²) ]=-6xy/[6x (x²-y²) = y / (y²-x²)

г

(b+3) / 9 (b-3) - (b-1) / (b-3) (b+3) = [ (b+3) ²-9 (b-1) ]/[9 (b²-9) ]=

= (b²+6b+9-9b+9) / [9 (b²-9) ] = (b²-3b+18) / [9 (b²-9) ]