Substitute in Algebraic Expressions

To replace a variable (letter) in an expression or equation with a specific numerical value

• Substitute

• Like Terms

• Algebraic Expression

• Constant

Plugging in a number for a variable is called

• operation

• evaluation

• substitution

• solving

What is a math problem with variable(s) in it called?

• common expression

• numerical expression

• equivalent expression

• algebraic expression

Define substitute.

• the number multiplied by a variable

• to replace a variable with a value or an expression

• a number standing alone

• to find the value of an expression

Mathematical Equivalence

OFF

What is the value of 2a - 3b + 6 when a = 2 and b = -5?

Mathematical Equivalence

ON

Evaluate 2x + 5y - 4 when x = 11 and y = 3

Mathematical Equivalence

ON

Evaluate 8.7j – 9.8k when j = 7 and k = 4.

Mathematical Equivalence

ON

Answer explanation

Evaluate 8.7j – 9.8k when j = 7 and k = 4.

First, substitute for j and k:

8.7(7) - 9.8(4) then multiply.

60.9 - 39.2 and finally subtract

21.7

Tags

CCSS.MATH.CONTENT.7.EE.B.4.a

Mathematical Equivalence

ON

Define variable

• a letter in the alphabet

• a letter or symbol standing for an unknown value

• a letter to grandma

• a letter to Santa