Let A = {a, b, c, d} and define a relation R on A as follows: R = {(a, a), (b, b), (b, d), (c, c), (d, b), (d, d)}. It is a fact that R is an equivalence relation on A. Use set-roster notation to write the equivalence classes of R.

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Find the commission on a $590.00 sale if the commission is 15%.