题目分解因式:(1)−2a+32ab2(1)-2a+32ab^{2}(1)−2a+32ab2；(2)x(y2+9)−6xy(2)x(y^{2}+9)-6xy(2)x(y2+9)−6xy；(3)y(y+4)−4(y+1)(3)y\left(y+4\right)-4\left(y+1\right)(3)y(y+4)−4(y+1).知识点：提公因式法章节：数与式 / 因式分解
