Select all of the following that are quadratic equations.
3x ^2 + 5x - 7 = 0
x ^3 - 2x ^2 + 1 = 0
2x - 1 = 0
5x ^2+ 15x = 0
6x - 1 = 4x + 7
x ^2 - 4x = 4x + 7

Handsome jack is buying a pony made of diamonds. the price of the pony is p dollars, and jack also has to pay a 25% diamond pony tax. which of the following expressions could represent how much jack pays in total for the pony?

Which best explains why this triangle is or is not a right triangle ?

One positive integer is 2 less than another. the product of the two integers is 24. what are the integers?