Carla is fundraising for her school. She buys t-shirts for $7.50 each and then she sells the t-shirts with a markup of 150%. What is the selling price of each t-shirt?

C. f(x)=-3(x+7)(x+4)

Step-by-step explanation:

x-intercept means the value of x where the functions touches the x axis.

The function touches x axis at two places, x=-7 and x=-4 ie. both -7 and -4 are the roots of the equation.

And the terms (x+7) and (x+4) are the factors of the function f(x),

Only one such case exists where (x+7) and (x+4) are there as factors, ie. Option C.

Therefore, C.-3(x+7)(x+4).