Add -24x²y to the difference obtain by subtracting -17x²y from -9x²y

What is the probability of rolling a single die greater than 4

What is the sum of these mixed numbers 2 1/8 + 4 3/8

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