Question

(12m² -27) = ?

(i) (2m-3)(3m-9)

(ii) 3(2m-9)(3m-1)

(iii) 3(2m-3)(2m+3)

(iv) None of these

Answer 1

(iii) 3(2m-3)(2m+3)

By taking 3 as the common factor we get,

By using the formula a² – b² = (a – b) (a + b)

(12m² -27) 

= 3(4m² -9)

= 3(2m -3) (2m + 3)