1. a math sentence that uses letters and operation signs asking price
2. selling price; cost plus markup
discount
3. a reduction of the selling price
algebraic expression
4. amount added to the cost of an item to get its selling price
variable
5. an equation that shows how a variable is related to other variables
rule
6. a quantity capable of assuming any of a set of values
markup

choice b is correct

step-by-step explanation:

we have been given the following system of linear inequalities;

we are required to graphically determine the solution to these system of inequalities. using a graphing tool, the solution is as shown in the attachment below;

this is a direct variation proportion. y = kx

y is the total amount due, k is the constant of variation, and x is the number of texts sent.

plug in the 3.20 and the 16 to solve for the "k". this is the constant of proportionality. it is the value that will not change.

3.20 = k(16). solving you get $.20 per text.

the equation would then be y = .20x

this is a good question! i’ll do some research and what i find, i’ll contact you asap when i have something! ✊