+11912 iii) 25m^2 + 30m + 9
To factories such question I used the identity x^2 + (a+b)x + ab
but in this one I don't understand that to do becoz 9 had only two factors that's 3x3=9 and 9x1=9 but both of thes don't add up giving 30 like 3+3 is not 30 and 9+1 is not 30.
i have no idea how to solve this!
+129852 This one is known as a "perfect square" trinomial
When the first and last terms are perfect squares (which they are)...always try this factorization..
Take the square root of the first term = 5m and the square root of the last term = 9
Write them twice separated by a "+" sign
(5m + 3) (5m + 3) ....notice that when we expand this we get
25m^2 + 15m + 15m + 9 = 25m^2 + 30m + 9....just what we started with...!!
As you improve your factoring skills, these will be easy to recognize....don't worry about it too much if you don't see it right away, right now...!!!
Also...if the middle term had been -30m we would have just written (5m - 3) (5m - 3) ...
+129852 This one is known as a "perfect square" trinomial
When the first and last terms are perfect squares (which they are)...always try this factorization..
Take the square root of the first term = 5m and the square root of the last term = 9
Write them twice separated by a "+" sign
(5m + 3) (5m + 3) ....notice that when we expand this we get
25m^2 + 15m + 15m + 9 = 25m^2 + 30m + 9....just what we started with...!!
As you improve your factoring skills, these will be easy to recognize....don't worry about it too much if you don't see it right away, right now...!!!
Also...if the middle term had been -30m we would have just written (5m - 3) (5m - 3) ...
