At a party 28 handshakes were exchanged. each person shook hands exactly once with each of the others. how many people were present?

Given that the area of a trapezoid is given by the formula A = 1 2 h (b1 + b2), what is the value of A if h = 2 cm, b1 = 3, and b2 = 4?

Explain how to use mental math to express 12/25 as a percent

How do I find the base of a triangle and the remaining side lengths?

Nine tens three ones

What is the sum of the geometric sequence 1,3,9 ... if there were 11 terms?

The sequence below is arithmetic {1,8,27,64}

Angles α and b are the two acute angles in a right triangle. Use the relationship between sine and cosine to find the value of b if b < α. sin (x 2 + 2x) = cos (2x + 3x 2)

Kevin has mowed 40% of the lawn. If he has been mowing for 20 minutes, how long will it take him to mow in a hour?

How to solve - x^2-2x=5?

Part A: Create a system of linear equations with no solution. In two or more complete sentences, explain the specific characteristics that you included in each equation to ensure that the system would not have a solution.