Why do we use the quadratic formula as opposed to trying to solve using factoring

My favorite songstress gives away 25% of this side of her signature fragrance collection to her charity last month her sales were 1200 how much of her sales did she donate

The base of a triangle exceeds the height by 7 centimeters. if the area is 400 square centimeters, find the length of the base and the height of the triangle.

Beth divided 9 ounces of her granola recipe into 4 equal-sized amounts. she placed the amounts into individual bowls. the fraction 9/4 represents the number of ounces of granola in each bowl. which other number represents the amount of granola beth has in each bowl? (a) 1 1/4 (b) 2 1/4 (c) 1 3/4 (d) 3 3/4 i need !