Matek spends 4/5 of his homework time on math. He spends 1/12 of it on writing. What fraction of his homework time is spent on math or writing? Simplify the answer if possible.

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

Haruka hiked several kilometers in the morning. she hiked only 66 kilometers in the afternoon, which was 25% less than she had hiked in the morning. how many kilometers did haruka hike in all?

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?