Sophia Learning, College Algebra, Milestone 3, WITH ANSWERS

The graph of a linear function passes through the points and . Find the slope of this function. •••• CORRECT RATIONALE CONCEPT Determining Slope 2 The prices for a loaf of bread and a gallon of milk for two supermarkets are shown below. Since we have two points from a linear function, we can use the slope formula to find the slope of the line. Now that the numbers are plugged in, evaluate the subtraction in both the numerator and the denominator. In the numerator, the difference in coordinates is minus , or . In the denominator, the difference in coordinates is minus , which is the same as plus , or . The slope of the line is . The slope is the difference in coordinates from the two points divided by the difference in coordinates from the same two points. When plugging in the values it is important to be consistent with which coordinates are subtracted in the calculations. A B Bread $2.20 $2.50 Milk $3.60 $3.40 Mary needs to buy bread and milk for her church picnic. At Supermarket A, she would pay $44.20. At Supermarket B, she would pay $44.70. Which of the following system of equations represents this situation? •• CORRECT •• RATIONALE In general, the equation to represent the total cost of buying bread and milk would be the sum of the cost for bread and cost for milk. To find the cost of bread and milk, first define variables to represent the amount of bread and milk. Here, will represent bread, and will represent milk. Both and will be multiplied by their respective prices.