Question

Take the problem y=4x^2-42x+54

1. I get the factors, -36 and -6, they multiply to 216 and add to -42
2. I do the punnet square method, but I can't solve it
3. Equals 2(2x-3)(x-9)
Question: How do I do the punnet square in a situation like this where there are number s outside of the parentheses?

Answer 1

Answer: y = 2(2x^2 - 21x +27) this should help you do the punnet square if you focus inside the parenthesis

Explanation:

for y = 4x^2 - 42x + 54 we can factor out a 2 so

y = 2(2x^2 - 21x + 27)

More to the answer...

We can seperate - 21x into -3x and -18x (focusing on the inside of the parenthesis)

2x^2 -3x -18x + 27 for 2x^2 - 3x we can factor out an x and for -18x + 27 we can factor out -9

2( x(2x-3) -9(2x-3) ) we can factor out 2x -3 so now it is

2(2x-3)(x-9)