Transcript
Download 52.14 Kb.
|
801094-1132015-101105-AM-618035631
- Navigate this page:
- Question
ReviewQuestion is displayed with answer choices. Question text: Evaluate the following expression for p = 4. 10 minus 2p Answer choices: 8 2 32 18 Correct answer: 2. Substitute 4 for the variable, p, to get 10 minus 2 times 4. To simplify, follow the order of operations. Multiply 2 times 4 to get 8, and then take 10 minus 8 to get 2. Mario will have $2.00 left after buying the pizza cutters. If you are asked to evaluate an expression for more than one value, you can create a table to organize the information. Text reads: 2x + 4. To evaluate 2x + 4 for x = 0, x = 1, x = 2, x = 3, and x = 4, create a table with one column that lists all of the possible x- values, and a second column where you can record the corresponding values of 2x + 4. Table appears:
Now, evaluate the expression for each x-value. If x is 0, plug 0 in for x in the expression to get 2 times 0 + 4, and then use the order of operations to simplify the problem. Multiply 2 times 0, and then add 4 to get 4. Text reads: 2x + 4 = 2 times 0 + 4 = 0 + 4 = 4 This means that when x = 0, 2x + 4 = 4. Now evaluate the expression for each of the other x-values in the table. When x = 1, 2x + 4 = 6. Text reads: 2x + 4 = 2 times 1 + 4 = 2 + 4 = 6 When x = 2, 2x + 4 = 8. Text reads: 2x + 4 = 2 times 2 + 4 = 4 + 4 = 8 When x = 3, 2x + 4 = 10. Text reads: 2x + 4 = 2 times 3 + 4 = 6 + 4 = 10 When x = 4, 2x + 4 = 12. Text reads: 2x + 4 = 2 times 4 + 4 = 8 + 4 = 12 The table of values is now complete. Table now reads:
You can use algebraic expressions and tables to solve real-world problems. For instance, if Mario has 5 sprockets, and his robot friend Wolfgang offers to give Mario half of his sprockets, can you think of an expression that would represent the number of sprockets Mario will have in total? Text reads: Mario has 5 sprockets. Wolfgang offers to give Mario half of his sprockets. If you use the variable w to represent the number of sprockets that Wolfgang has, you can write the expression 5 + w divided by 2 to represent the total number of sprockets Mario will have. Text reads: 5 + w divided by 2. If Mario knows that Wolfgang has either 2, 4, 6, or 8 sprockets, you can create a table and solve for each of these values. Table appears:
QuestionQuestion is displayed with answer choices. Question text: Match the w-value to the corresponding value of the algebraic expression. Answer choices: If w = 2, If w = 4, If w = 6, If w = 8, 5 + w divided by 2 = 6 5 + w divided by 2 = 7 5 + w divided by 2 = 8 5 + w divided by 2 = 9 Correct answers: If w = 2, 5 + w divided by 2 = 6. If w = 4, 5 + w divided by 2 = 7. If w = 6, 5 + w divided by 2 = 8. If w = 8, 5 + w divided by 2 = 9. Evaluate by substituting each w-value into 5 + w divided by 2 and use the order of operations to simplify and find out how many sprockets Mario will have. The robot Mario appears, and the text on his screen reads: 3n + 6. As Mario learned, evaluating an algebraic expression is as simple as following a recipe. Once you know the value of your variable—the secret ingredient—you can plug it in to the expression and follow the order of operations to simplify. Text reads: 3 times 2 + 6. Knowing how to write and evaluate expressions is one of the basic foundations for algebra, and you can use this knowledge to solve problems in the real world as well as the classroom. Text reads: algebra, real-world problems. As for Mario, he was shipped off to Pumpernickel’s Pizza Parlor, where he began work as an entry-level pizza maker. But when the owner saw that Mario can use algebraic expressions and tables to save the pizza parlor money, he immediately promoted Mario to supervising pizza robot. That just goes to show that hard work and mathematical know-how can really pay off! © 2012 Connections Education LLC. All rights reserved. Download 52.14 Kb. Share with your friends:
|