Ava’s lunch bill was $8.70 and Allanah’s was $10.30. The girls’ uncle paid for the lunches and left a 15% tip. What amount did the girl’s uncle leave for a tip? A) $2.85
B) $3.00
C) $21.85
D) $19.00
I appreciate anyone who answers this. ;)

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Solve 3x-18=2y and 5x-6y=6 by elimination show work

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books