The quadratic 3x^2-24x+72 can be written in the form a(x+b)^2+c where a, b, and c, are constants. What is a+b+c?

thanks so much for the help!

3x^2 - 24x + 72 factor out the 3

3 [ x^2 - 8x + 24 ]

Take 1/2 of 8 = 4........square it = 16....add and subtract it

3 [ x^2 - 8x + 16 + 24 - 16 ]

Factor the first three terms and simplify

3 [ ( x - 4)^2 + 8 ]

3 (x - 4)^2 + 24

a + b + c =

3 + (-4) + 24 =

-1 + 24

23