Evaluating Expressions with Substitution

Write the phrase as an expression. "the product of a number m and 23"

• m⋅23 or 23m

• 23m

• m+23

• m⋅23

When using the substitution method, you will ____.

• eliminate one of the variables altogether.

• replace one variable with an equivalent expression containing the other variable.

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Evaluate 12-2g for g =3 

• 11

• 6

• 8

• 7

If a=4,b=5 and c=6,find 2c-a-b

• 4

• 3

• 6

What is the value of a numerical expression?

• The result of replacing some (or all) of the numbers in a numerical expression with variables.

• The number found by evaluating the expression

• A symbol (such as a letter) that represents a number

• Each summand of an expression in expanded form

What is an equivalent expression?

• The number before the variable

• An expression in expanded form with all like terms collected.

• Both expressions evaluate to the same number, no matter the substitution of numbers in variables.

• A number, or it is any combination of sums, differences, products, or divisions of numbers that evaluates to a number.

2(z+y); use y=4 and z=1

• 9

• 10

• 13

• 15

p(m+2); use m=1 and p=5

• 11

• 15

• 14

• 18

x+2y; use x=4 and y=3

• 8

• 7

• 10

• 16

y+x-x, use x=1 and y=1

• 6

• 1

• 2

• 3