Question

Quadratic factorisation Question, help please.

Answer 1

3x^2 + 5x + 2 

a = 3 , b = 5 , c = 2 

Start by mulitplying a*c = 3 * 2 = 6

Now find two number that multiply to 6 and add up to b or 5 

We could use 2 and 3 because ....

   3 + 2 = 5 
   3 * 2 = 6

Now you rewrite....

3x^2 + 3x + 2x + 2 

Now pull out common factors...

3x ( x + 1 )  + 2 ( x + 1)

The factors of this expression is ( 3x + 2 ) ( x + 1)