on Saturday afternoon, six friends agreed to call each other. each friend talked to every other friend once. how many phone calls were made?

What is a terminating decimal

If 20+20 is 40 percent what is 20 of half percent.

Simplify by combining like terms: 2x + 1 + 7x

Consider the equation 40x - 25y = 15 David wrote a second equation to create a system that has infinitely many solutions. Which of these could be the equation that David wrote? A) 8x - 5y = 3 B) 8x + 5y = 3 C) 8x + 5y = - 3 D) - 8x + 5y = - 3

Is the relation a function? Select Yes or No for each relation. (3,3), (3,-2), (-2,4), and (1,-6) (3,3), (5,-2), (-2,4), and (1,-2) (3,3), (5,-2), (-2,4), and (5,9) (3,3), (5,-2), (-2,4), and (4,9)

3. Which of the following is equivalent to 3 (y - 1 + 2y) ? A. 3y - 9 B. 6y - 3 C. 9y - 3 D. 3y - 3

If y various directly with x, write an equation for the direct variations. The find each value. 1.) If y = - 4 when x = 10, find y when x = 5 2.) If y = 12 When x = - 15, find y when x = 2 3.

89 (54x - 36) + 2 = - 3/4 (-40 + 16x) + 90xsolve for x

The ratio of cars to vans in a parking lot is 1 to 4. If there are 40 cars and vans in the parking lot altogether then how many vans are there?

Geoffrey's babysitter stayed from 6:25 P. M. until 10:40 P. M. For how much time does the babysitter need to be paid?