因式分解急問!!!!!!!!!!!!!!!!!!!!!!!

(1)
(a) (x+3)^2
(b) (x-4)^2
(c) (x+9)^2
(d) 題目係唔係x^2-25x+169? 如困係x^2-25x+169, 咁就係(x-13)^2

(2)
(a) (x+8)(x-8)
(b) (9+5)(9-5)
(c) 4x^2-25y^2
=(2x)^2 - (5y)^2
=(2x+5y)(2x-5y)

(3)
(a) (x+2)(x+5)
(b) (x-5)(x-1)
(c) (2x+1)(x+1)
(d) 因為: a^3 + b^3 = (a+b) * (a^2 -ab + b^2)
所以: x^3+64 = x^3 + 4^3 = (x+4) * (x^2 - 4x + 4^2)


(a+b)^2 = a^2 + 2ab + b^2
(a-b)^2 = a^2 - 2ab + b^2
(a+b)(a-b) = a^2 - b ^2
a^3 + b^3 = (a+b) * (a^2 -ab + b^2)

1a)x^2+6x+9=(x+3)^2
b)x^2-8x+16=(x-4)^2
c)x^2+18x+81=(x+9)^2
d)x^2-25x+169=?
2a)x^2-64=(x+8)(x-8)
b)81x^2-25=(9x+5)(9x-5)
c)4x^2-25y^2=(2x+5y)(2x-5y)
3a)x^2+7x+10=(x+2)(x+5)
b)x^2-6x+5=?
c)2x^2+3x+1=(2x+1)(x+1)
d)x^3+64=?