factorise.... l will give brainliest

Answer:
(a-12b) (a-3b)
Step-by-step explanation:
[tex]a^{2}[/tex] - 15ab + 36[tex]b^{2}[/tex]
[tex]a^{2}[/tex] × 36[tex]b^{2}[/tex] = 36[tex]a^{2} b^{2}[/tex]
(- 12ab) + (- 3ab) = (-15ab)
(- 12ab) × (- 3ab) = 36[tex]a^{2} b^{2}[/tex]
[tex]a^{2}[/tex] - 12ab - 3ab + 36[tex]a^{2} b^{2}[/tex]
a (a -12b) -3 (a-12b)
(a-12b) (a-3b)