SOLUTION: factorise: 1) 5m2-45n2 2)10m2n2-7mn-12 3) 9a2-(3a-2b)2 4)12x2+35xy+18y2

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: factorise: 1) 5m2-45n2 2)10m2n2-7mn-12 3) 9a2-(3a-2b)2 4)12x2+35xy+18y2       Log On


   

Question 198658: factorise:
1) 5m2-45n2
2)10m2n2-7mn-12
3) 9a2-(3a-2b)2
4)12x2+35xy+18y2
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1) 5m^2-45n^2
Factor out 5
5(m^2 - 9n^2)
Factor difference of squares
5(m - 3n)(m + 3n)
:
2)10m^2n^2 - 7mn - 12
mn(10mn - 7) - 12
:
3) 9a^2-(3a-2b)^2
9a^2 - (9a^2 - 12ab + 4b^2);square 3a-2b
9a^2 - 9a^2 + 12ab - 4b^2;removing brackets changes the signs
12ab - 4b^2
4b(3a- b)
:
4)12x^2 + 35xy + 18y^2
This can be factored
(4x + 9y)(3x + 2y)