Can someone help me with these algebraic expressions? And can you please EXPLAIN OR SHOW YOUR WORK!

1. f(x) = 3x^2 +13x -10

2. f(x) = 2x^2+4x-16

3. f(x) = 4x^2 - 81

Thanks!

What number should be added to both sides of the equation to complete this square? x^2-10x=7

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

Sam is picking fruit from a basket that contains many different kinds of fruit. which set of events is independent?