Final answer:
The total cost for tissues can be represented by the equation y = mx + b, where y is the total cost, x is the number of boxes, m is the cost per box, and b is the delivery cost. In this case, the cost per box is 1.5 and the delivery cost is $30. Therefore, the equation that represents the total cost for tissues is y = 1.5x + 30.
Step-by-step explanation:
The total cost for tissues can be represented by the equation y = mx + b, where y is the total cost, x is the number of boxes, m is the cost per box, and b is the delivery cost.
In this case, the cost per box is represented by the slope of the equation. To find the slope, we can use the formula: m = (y2 - y1) / (x2 - x1), where (x1, y1) represents the values from the first month and (x2, y2) represents the values from the second month.
- From the first month: x1 = 300 boxes and y1 = $480
- From the second month: x2 = 250 boxes and y2 = $405
Plugging these values into the slope formula, we get: m = ($405 - $480) / (250 - 300) = -75 / -50 = 1.5
The delivery cost, represented by b, can be found by substituting the values from either month into the equation and solving for b. Let's use the values from the first month:
$480 = 1.5(300) + b
Simplifying the equation, we get: 480 = 450 + b
Subtracting 450 from both sides, we get: b = 480 - 450 = $30
Therefore, the equation that represents the total cost for tissues is: y = 1.5x + 30