а) 4y-(3y-(2y+1)) = 4y-(3y-2y-1) = 4y-3y+2y+1 = 3y+1
б) a-(2x-(2a-x)) = a-(2x-2a+x) = a-2x+2a-x =3a-3x
в) 3m-(3m+(3m-(m+3))) = 3m-(3m+(2m-3)) = 3m-(3m+2m-3) = 3m-3m-2m+3 = -2m+3
г) b-(2c-(3b+(4c-5b))) = b-(2c-(3b+4c-5b)) = b-(2c-3b-4c+5b) = b-2c+3b+4c-5b = -b+2c