there is a 40% chance that the randomly selected child will have a speaking part.
(it is actually 51.11, but since you're rounding it will be 51)
the standard form is: y = -3x² +18x -24.
given is y = -3(x-2)(x-4)
using foil method to expand the parentheses: -
y = -3(x-2)(x-4)
y = -3(x² -2x -4x +8)
combining like terms: -
y = -3(x² -6x +8)
distributing -3 to the terms inside parentheses: -
y = -3x² +18x -24.
hence, standard form is: y = -3x² +18x -24.