6x제곱-9xy,6x제곱-2xy 10a제곱-2ab,-15x제곱+6xy 2a제곱+4ab-15b제곱,18x제곱-7xy-8x 5a제곱+4a,6a제곱-7ab-b제곱 4ab+2,-2x+5,-3분의8x+2y-4,6a-3b-12 6x+2
당신은 어느 그룹입니까?