How can i prove that: abs(x+y) less than or equal to abs(x) + abs (y)?

Idont understand math at all! : o( use this scenario to answer the remaining questions: brenton purchased a new bedroom set for $4,500.00. he lives in arizona and pays a 8.75% sales tax. if he made a 50% down payment and financed the rest, what amount did he finance? what is the total sales tax brenton will pay? enter your answer in currency format, round to the nearest cent. what was brenton's total amount financed? enter your answer in currency format, round to the nearest cent.

Erin bought christmas cards for $2 each to send to her family and friends. which variable is the dependent variable?

What is the radius of a circle with an area of 78.5 cubic inches? use 3.14 for pie