There are 10 marbles in a bag, and the marbles are either red or blue. eric will randomly choose two marbles from the bag, without replacing the first one. if the probability of both marbles' being red is
2
15, how many red marbles are in the bag?

Follow these steps using the algebra tiles to solve the equation −5x + (−2) = −2x + 4. 1. add 5 positive x-tiles to both sides and create zero pairs. 2. add 4 negative unit tiles to both sides and create zero pairs. 3. divide the unit tiles evenly among the x-tiles. x =

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.