Please help due today Prove the sum of two rational numbers is rational where a, b, c, and d are integers and b and d cannot be zero.

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

Which two transformations are applied to pentagon abcde to create a'b'c'd'e'? (4 points) translated according to the rule (x, y) ? (x + 8, y + 2) and reflected across the x-axis translated according to the rule (x, y) ? (x + 2, y + 8) and reflected across the y-axis translated according to the rule (x, y) ? (x + 8, y + 2) and reflected across the y-axis translated according to the rule (x, y) ? (x + 2, y + 8) and reflected across the x-axis

Which is the scale factor proportion for the enlargement shown?