It looks like you're given

Then by the additivity of definite integrals this is the same as

(presumably this is what the hint suggests to use)
Then by the fundamental theorem of calculus, we have

The answer is 51%
Because you have to divide 2,300/4500=0.51 which gives you 51%
Answer: Anna could buy 5 sweatshirts for $75.
Step-by-step explanation:
lets figure out the price of one sweatshirt.
45/3 = 15
one sweatshirt is $15
5*15=75
so 5 sweatshirts cost $75