What is the value of the underline digit 584.2

In the xy-plane, if the parabola with equation passes through the point (-1, -1), which of the following must be true?

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. after tax the total is 45.99. what percentage of the subtotal is the total?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'