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hendricks_beginning_algebra_1e_ch1_3

64 Chapter 1 Real Numbers and Algebraic Expressions Student Check 4 Evaluate each expression at the given values. a. 1(x1 - x2)2 + (y1 - y2)2, for x1=-3, x2 = 2, y1 = 8, y2=-4 b. ux - 2u x + 2 , for x=-2, -1, 0, 1, 2 Applications Multiplication and division of real numbers occur in real life through various types of problems. Multiplication is needed to calculate the area and volume of geometric shapes. Division is needed to calculate the average of a group of numbers. ������������������������ The average of a group of two or more values is the sum of the values divided by the number of values. For example, the average of 50 and 100 is 50 + 100 2 = 150 2 = 75. Division is also needed to find the percent change in a value. �������������������� Percent Change If an original value has taken on a new value, then the percent change is calculated as new value - original value original value   or   change in value original value For example, if the price of a $30 item is on sale for $24, then the percent change in the price is new - original original = 24 - 30 30 = -6 30 =-0.20 or a decrease of 20% �� ������������������������ ������������������ Solve each problem. 5a. The area of a rectangle is length times width. Write an equation that represents the area of a rectangle, where l is the length and w is the width of the rectangle. Use the equation to find the area of an iPad which has a length of 9.56 in. and a width of 7.47 in. Round to two decimal places. Solution 5a. The area of a rectangle can be written as A = (l)(w) or A = lw. To find the area of an iPad, replace l with 9.56 and w with 7.47. A = lw A = (9.56)(7.47) A = 71.41 So, the area of an iPad is 71.41 in.2 Objective 5 ▶ Solve real-life problems.


hendricks_beginning_algebra_1e_ch1_3
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