Question

Factorise 3x^2+180x-4212

Answer 1

Answer:

3(x-18)(x+78)

Step-by-step explanation:

3x^2 + 180x - 4212

 3 ( x^2 + 60x -1404 )

So now we need two numbers which when multiply gives -1404 and when add gives 60.

We only know the range in which those number lies which in this case is  1⊇ x ⊆1404 , else its a hit and trial way to find them.

The two numbers are :

-18 and 78.

3 ( x - 18 ) ( x + 78 )