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801094-1132015-101105-AM-618035631
ReviewQuestion is displayed with answer choices. Question text: What is the variable in this algebraic expression? 5a minus 6 Answer choices: 5 a minus 6 Correct answer: a. If you tell Mario that you want pepperoni on your pizza, he can plug pepperoni into his recipe where it says topping and follow the steps to make you a great pepperoni pizza. The robot Mario appears, and the text on his screen reads: make pizza. Similarly, to evaluate an algebraic expression, replace the variable with the given number, and then use the order of operations to simplify the expression. To evaluate 9x + 1 for x = 4, plug the number 4 into the expression in place of the x, to get the expression 9 times 4 + 1. Text reads: Evaluate 9x + 1 for x = 4. 9x + 1 4 9 times 4 + 1 Follow the order of operations and multiply 9 by 4 to get 36, and then add 1, to get 37. Text reads: 36 + 1 37 Evaluating expressions is even easier for Mario to do than making pizza! Algebraic expressions are often used to represent real-life problems in which you are missing one or more pieces of information. For instance, suppose Mario has $10.00 and wants to buy 2 titanium pizza cutters from Robot Hut, but he doesn’t know how much they will cost. Text reads: Mario has $10.00 and wants to buy 2 pizza cutters. A 10 dollar bill appears next to 2 pizza cutters. What expression can you write to represent how much money Mario will have, if any, after he buys the pizza cutters? If you use the variable p to represent the cost of each pizza cutter, the money Mario will have after his purchase is equal to 10 minus 2p. Text reads: 10 minus 2p. Notice that when you multiply a number, like 2, times a variable, like p, you do not need to write a multiplication sign to show the operation. 2p is highlighted. A number placed in front of a variable is called a coefficient. Text reads: coefficient. An arrow points to the 2 in 2p. A coefficient is a multiplier of the variable, and it indicates how many of that variable there are. If Mario finds out that the pizza cutters cost $4.00 each, he can evaluate 10 minus 2p for p = 4. Text reads: Evaluate 10 minus 2p for p = 4. Download 52.14 Kb. Share with your friends:
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