若4x^2-4x-15
问题描述:
若4x^2-4x-15
答
4x^2-4x-15(2x-5)(2x+3)则
2x-5或
2x+3√(4x^2-12x+9)+√(4x^2-20x+25)
=√((2x - 3)^2)+√((2x-5)^2)
=2x-3-(2x-5)
=2x-3-2x+5
=2
答
4x^2-4x-15