Help againnn plzzz

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?

In right triangle xyz, the right angle is located at vertex y. the length of line segment xy is 12.4 cm. the length of line segment yz is 15.1 cm. which is the approximate measure of angle yzx? 34.8° 39.4° 50.6° 55.2°

The function g(x) is graphed. which statements about the function are true? check all that apply.