100 - (12 + 7(4) + 2(6) + 15)
What is the answer?

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

What power can you write to represent the volume of the cube shown? write the power as an expression with a base and an exponent and then find the volume of the cube

The discrete random variables x and y take integer values with joint probability distribution given by f (x,y) = a(y−x+1) 0 ≤ x ≤ y ≤ 2 or =0 otherwise, where a is a constant. 1 tabulate the distribution and show that a = 0.1.2 find the marginal distributions of x and y. 3 calculate cov(x,y).4 state, giving a reason, whether x and y are independent. 5 calculate e(y|x = 1).