Evaluating Algebraic Expressions

Question 1

In order to solve expressions with variables, you must be given the value of the variables. For example, it is impossible to solve: 4n – 1 without knowing the value of the n. Now if I tell you the value of the n is 3, you CAN solve it. In order to solve this, follow these 2 simple steps: Substitute & Compute

1.) Substitute (replace) the variable n with the number given.
Remember this can also be written: 4(3) – 1

2.) Compute. Solve the expression using ORDER OF OPERATIONS.

Answer 1

Solution: 11

Question 2

Answer: z=8
16-z+4

Answer 2

Solution: 12

Question 3

Answer: t=3
48/s+8xt

Answer 3

Solution: 28

Question 4

Fill in the blanks:
You can solve many real-world problems by _______________ them into algebraic ______________ and then _____________ the expressions.

Answer 4

You can solve many real-world problems by TRANSLATING them into algebraic EXPRESSIONS and then EVALUATING the expressions.

Question 5

Answer the question and fill in the blanks:
Step 1: Substitute the variable (m) with the number of minutes.

1.75 + 0.15m _____________________

Step 2: Compute using the order of operations.

Solution: The cost for a phone call that lasts 40 minutes is $________

Answer 5

Step 1: Substitute the variable (m) with the number of minutes.

1.75 + 0.15m=1.75+0.15(40)

Step 2: Compute using the order of operations. Show your work:

Solution: The cost for a phone call that lasts 40 minutes is $7.75

Question 6

You can solve many real world problems by _______________ them into algebraic ______________ and then _____________ the expressions.

Answer 6

You can solve many real world problems by _______________ them into algebraic ______________ and then _____________ the expressions.

Question 7

Here’s an example situation to solve: Mrs. Oursler’s cell phone company uses the following expression to calculate the cost of a long distance phone call: 1.75 + 0.15m. The fixed cost (constant that doesn’t change) is $1.75, and the variable m represents the number of minutes of a call. Use the expression to find the cost of a phone call that lasts 40 minutes. The m (minutes) is the variable because its amount changes (varies; not fixed).

Strategy: Substitute and Compute
Step 1: Substitute the variable (m) with the number of minutes. 1.75 + 0.15m _____________________
Step 2: Compute using the order of operations.
Solution: The cost for a phone call that lasts 40 minutes is $________

Answer 7

Here’s an example situation to solve: Mrs. Oursler’s cell phone company uses the following expression to calculate the cost of a long distance phone call: 1.75 + 0.15m. The fixed cost (constant that doesn’t change) is $1.75, and the variable m represents the number of minutes of a call. Use the expression to find the cost of a phone call that lasts 40 minutes. The m (minutes) is the variable because its amount changes (varies; not fixed).

Strategy: Substitute and Compute
Step 1: Substitute the variable (m) with the number of minutes. 1.75 + 0.15m 1.75+0.15 (40)
Step 2: Compute using the order of operations.
Solution: The cost for a phone call that lasts 40 minutes is $7.75