What does a variable allow you to do that you couldn't do before

Y is 2.5 when x is 5, and y varies directly with x. Find y when x is 10.

Simplify the expression: (x^2-8x+16/3x^2y) / (ax-4x/6xy^2)

Subtracting with zeroes

Over the last week, the daily low temperatures in degrees Fahrenheit have been - 4,6.2,18 1/2,-5.9,21,-1/4,1.75. List these numbers in order from least to greatest

Use the quadratic formula to solve 3y^2-9y-30=0 20 pts

Find the perimeter of triangle abc with vertices a (-1,2) b (3,6) c (3,-2)

Show steps 3y - 4 < or equal to 5

What is greater - 1.44 or - 1 1/4

Court time is selling tennis rackets for $64.99. The cost to court time is $37.48 per racket. Overhead is estimated to be 20 percent of the selling price. What is the net profit rate?

25 is on sale for 30% off. What is the sale price