Which expression is an equivalent expression of 12x + 10 + 4y?

a: 2(6x + 2y + 6)
b: 3(4x + y + 10)
c: 2(6x + 4y + 8)
d: 2(6x + 5 + 2y)

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Solve each quadratic equation by factoring and using the zero product property. 10x + 6 = -2x^2 -2

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?