Practice to Practice Session #7

Practice to Practice Session #7

Simplifying and Evaluating Algebraic Expressions

Multiple Choice

Translate this phrase into an algebraic expression.

24 more than Victoria's test score.

Use d to represent Victoria's test score.

• 24x

• x - 24

• x + 24

• x/24

Multiple Choice

Translate this phrase into an algabraic expression.

78 less than Amari's test score

Use c to represent Amari's test score.

• c - 78

• c + 78

• c/78

• 78 - c

Multiple Choice

Translate this phrase into an algebraic expression.

8 less than the product of 4 and a number

Use the variable m to represent the unknown number.

• 4m + 8

• 8m - 4

• 8m + 4

• 4m - 8

Evaluating Algebraic Expressions

• When a question asks you to "evaluate" an expression, it is asking you to find a numerical (number) answer

• To evaluate an expression, replace the variable with the number value you are given

• Then use PEMDAS to simplify the result

Example 1: Simplify 3b + 10 when b = 8

Start by replacing b with 8, 3(8) + 10

Simplify using PEMDAS

3(8) + 10

= 24 + 10

= 34

Example 2: Evalute 2(x - 3) when x = 5

• Start by replaced x with 5.

• 2(5 - 3)

• Follow PEMDAS to simplify

• 2(2) = 4

Multiple Choice

Evaluate 3x - 7 if x = 6

• 9

• 11

• 29

• 25

Multiple Choice

Evaluate 3b - 5 if b = -2

• 1

• -11

• -1

• 27

Example 4: Evaluate the expression 5(x - 1) + 4 when x = 10

First, we replace our variable with the given value.

5(10 - 1) + 4

Then we simplify using PEMDAS!

5(9) + 4

= 45 + 4

= 49

Example 5: What is the value of 7(2x + y) when x = 4 and y = 6.

In some cases, there can be more than one variable in the expression.

In this case, you replace each variable with the given value.

For this example, we would replace x with 4 and y with 6.

 $7\left(2\cdot4+6\right)=7\left(8+6\right)=7\left(14\right)=98$  

Multiple Choice

Evaluate when a = 15:

2(a - 5) + 2

• 22

• 27

• 14

• 7

Multiple Choice

2x + 5(y - 1) when x=8 and y=5

• 20
• 31
• 36
• -4

Multiple Choice

Evaluate 2a + 4b

if a = 10 and b = 6

• 20

• 24

• 44

• 4

Example 6: What is the value of 6(2c + d) - c when c = 4 and d = 3?

First, we replace our variables with the given numbers.

 $6\left(2\cdot4+3\right)-4$  

Then we simplify using PEMDAS! 
6(8 + 3) - 4

6(11) - 4 
66 - 4
62

Example 7: What is the value of

 $4\left(3e-f\right)+e^2+2f\$  
when e = 6 and f = 4?

First, replace e with 6 and f with 4.

 $4\left(3\cdot6-4\right)+6^2+2\cdot4$  
Then simplify using PEMDAS! 

4(18 - 4) + 36 + 8 
=4(14) + 36 + 8 
=56 + 36 + 8 
= 100 

Multiple Choice

What is the value of

 $6\left(g\ +\ 4h\right)+\ h^2-5g\ when\ g\ =\ 5\ and\ h\ =\ 4?$  

• 37

• 117

• 131

• 135

Multiple Choice

Evaluate when x = 2 and y = 5:
2 + (12 - 5x) ⋅ 2y

• 22
• 40
• 142
• -86

Multiple Choice

2x + 3 + x²; for x = 4

• 17
• 27
• 19
• 25

Multiple Choice

Evaluate the expression for x = −4 and y = 4.

(x + 17) + (17 − y)

• 21

• 42

• 0

• 8

Multiple Choice

Evaluate the expression for x = −4 and y = 4.

(x + 17) + (17 − y)

• 21

• 42

• 0

• 8

Open Ended

Find the value of the expression when x = 4 and y =2.

 $5\left(x\ +\ 2y\right)\ +\ y^2-3x$