This is graphing and if you only want points ill report

 The variables are the Cost of the item, and the Total cost.

The other cost, the shipping is given here: $2. So that is not really a variable.

You can use almost any letters you'd like. I'm using C for the item's cost,  and T for the total cost in this equation:

C + 2 = T

This question seems to imply that only one item is in the order

Step-by-step explanation:

There may be other ways to do this, if multiple items are ordered.

The variables are the Cost of the item-- and how Many items are purchased.

The Total is also a variable that depends on how many and the cost of the items.

The other cost, the shipping might be a variable in other questions (not here) here: S could be a variable if it is a percentage ot the cost.

You can use almost any letters you'd like. I'm using C for the item's cost, M for the number of items, S for variable shipping, and T for the total cost in this equation:

M×C + S = T

the ratio of grapes to blueberries she should use is 12: 3

step-by-step explanation:

if mandie is making 15 cups of fruit salad, the ratio of grapes to blueberries she should use is 12: 3.

(a) {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …}

(b) $59 398

step-by-step explanation:

(a) the annual sequence of profits

aₙ = a₁rⁿ⁻¹

the model for the sequence of profits is {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …} .

(b) profit after 15 yr

  a₁ = $ 30 000

  r = 1.05

a₁₅ = 30 000 × 1.05¹⁴

a₁₅ = 30 000 × 1.979 93

a₁₅ = $59 398

the profit in year 15 will be $59 398.