15x(a-b)的平方-3y(b-a)的因式分解
=15x(a-b)²;+3y(a-b)
=3(a-b)(5ax+5bx+y)
把3x^2+12xy+11y^2因式分解
3x^2+12xy+11y^2
=3x^2+12xy+12y^2-y^2
=3(x+2y)^2-y^2
=[a(x+2y)+y][a(x+2y)-y]
a=根號3
把3x^2+12xy+11y^2在實數範圍內進行因式分解
3x^2+12xy+11y^2
=3x^2+12xy+12y^2-y^2
=3(x+2y)^2-y^2
=[根號3(x+2y)+y][根號3(x+2y)-y]