4x제곱-12xy+9y제곱,9x제곱-1,10x제곱-x-2,a제곱-6분의7a-2분의1,9b제곱-4a제곱,-2x제곱+13xy-21y제곱,a제곱-3분의2ab+9분의b제곱,10x제곱+3분의4xy-2분의1y제곱
당신은 어느 그룹입니까?