What are letters A, B, and C?

a. (3-7x) + (3-7x) + (3-7x) + (3-7x)

b. 4(3-7x)

c. 12 - 28x

Step-by-step explanation:

To find the perimeter of a square, you need to add up all the sides

a. Since a square has all equal sides you will need to write the expression four times: (3-7x) + (3-7x) + (3-7x) + (3-7x) = perimeter

b. Expressing this as a product, we can condense the formula to 4 multiplied by the expression since it is written four times: 4(3-7x) = perimeter

c. Using the distributive property, we can write the product 4(3-7x) from b. as: (4)(3) + (4)(-7x) = 12 + (-28x) = 12 - 28x = perimeter

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