Dell laptop with a retail price of $525 for only $393.75 what is the percent of change

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

If the measure of angle 1 is 110 degrees and the measure of angle 3 is (2 x+10 degree), what is the value of x?

In a 45-45-90 right triangle, what is the ratio of the length of one leg to the length of the other leg? а . 1: 2 в. 2: 1 с. 2: 1 d. 1: 1