Question

which of the following is the correct standard form of y=3(x-8)(x-5)

Answer 1

standard form is:
ax^2 + bx + c

So multiply/distribute everything
y = 3(x^2 - 5x - 8x + 40)
y = 3(x^2 - 13x + 40)
y = 3x^2 - 39x + 120