I need help! this question is from my iready eighth grade test and I don’t understand it!!

Solve with work adding cheese to a mcdonalds quarter pounder increases the fat content from 21g to 30g. what is the percent of change ?

Complete the solution of the equation. find the value of y when x equals -5. -4x - 8y = -52

21 type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar. the solution set of n2 - 14n = -45 is { (separate the solutions with a comma)