Question

分解因式，急

1. 1/25 x^2-9y^2

2. x-xy^2

3 2mx^2-4mx+2m

4. (x^2+1)^2-(y^2+1)^2

5. a^4-2a^2+1

6. (a+2b)^2-a-2b

另附PO垂直OR，OQ垂直PR，其中点到直线的距离有几条

Answer 1

(1/5x+3y)(1/5x-3y)
x(1+y)(1-y)
2m(x-1)^2
(x^2+y^2+2)(x+y)(x-y)
(a+1)^2(a-1)^2
(a+2b)(a+2b-1)