Factorising using identities

Factorise : x² - 9

• (x-3)(x-3)

• (x-3)(x+3)

• (x-3)(3-x)

• (x-3)²

x² + 2x +1

• (x+1)²

• (x-1)²

• (x+1)(x-1)

• none of these

(x² - 8x +16)

• (x+4)²

• (x-4)²

• (x+4)(x-4)

• can not be factorised.

x² + 15x + 50

• (x+3)(x+5)

• (x+30)(x+20)

• (x+30)(x-20)

• (x+5)(x+10)

x² y² - 25

• (xy + 5) ²

• (xy + 5)(xy - 5)

• (xy -5)(xy - 5)

• can not be factorised

m² + 9x + 14

• (m+3)²

• (m-3)²

• (m+2)(m+7)

• (m+4)(m+10)

(m^.m - 4m - 77)

• (m+4)(m+7)

• (m-11)(m+7)

• (m+11)(m-7)

• (m+11)(m+7)