Based on Pythagorean identities, which equation is true?
sin^ 0-1=cos^2
sec^2 0-tan^2 0=-1
-cos^2 0-1=-sin^2
cot²0-csc²a0=-1

What is the quotient of -3/8and-1/3?

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?