How do you know if a number is rational or irrational

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?

When you dilate a figure with a scale factor of 1/2, what will the dilated figure look like?                                                                                           a: the dilated figure will have side lengths that are half the length of the original side lengths.                                                                          b: the angles in the dilated figure will be half the measure of the original figure.                                                                                c: the dilated figure will have side lengths twice the length of the original.

What is the solution for the following system of equations? use any method to solve. y = -x +4 y = x - 2 a. ( 4 , -2) b. (2, 1) c. (3, 1) d.(3, -2)