Please help me solve this:

If the selling price of 12 books and 21 pens are 240$, and the selling price of 21 books and 12 pens are 222$. What is the price of one book and one pen?

Find the pattern and use it to list the nth term in the sequence. 6, 12, 20, 30, 42, 56, the nth term of the sequence is

Television sizes are based on the length of the diagonal of the television's rectangular screen. so, for example, a 70-inch television is a television having a diagonal screen length of 70 inches. if a 70 inch television's diagonal forms a 29°angle with the base of the screen, what is the vertical height (1) of the screen to the nearest inch? 70 inhin

How much orange juice do you need to make 2 servings of lemony orange slush?