Спрости вираз : а)-6а-b+5а-13b; б)(3--5r); в)-2x*(y-3)+x*(2y+1); г)5/8*(12m-2.2/3)+7/15*(2.1/7m-2.1/6)

A) -6a-b+5a-13b = -a-14b
б) (3-2r)-(8-5r) = 3-2r-8+5r = 3r-5
в) -2x*(y-3)+x*(2y+1) = -2xy+6x+2xy+x = 6x+x = 7x
г) 5/8*(12m-2.2/3)+7/15*(2.1/7m-2.1/6) = 7.5m-8/3+m-91/90 =8.5m-3.31/90.