1-1 Variables and Expressions Algebra I

1-1 Variables and Expressions Algebra I

What is an algebraic expression?

• Sums or products of numbers and variables

• terms can be numbers, variables, operations

• Recall that expressions DO NOT contain an = sign

Examples

• 4z (one term)

• 5x + 2 (two terms)

• r³+ 5x + 4 (three terms)

• 5x/4 - 1/3z (two terms)

Do you recall what exponents are?

• x³ means x times x times x

• 4/3y² means multiply 4/3 times y times y

Multiple Choice

What is 2³ ?

• 2 + 2 + 2 or 6

• 2 x 2 x 2 or 8

What are Powers, Exponents and Bases?

Translating Verbal Expressions to Algebraic Expressions

• Addition: more than, sum, plus, increased by, added to

• Subtraction: less than, subtracted from, decreased by, minus

• Multiplication: times, product of, multiplied by or simply of (2/3 of 6)

• Division: quotient of, divided by

Multiple Choice

Write and algebraic expression for

14 more than x

• 14x

• x + 14

• 14/x

• 14 - x

Multiple Choice

Write an algebraic expression for the product of x squared and 4

• 2x + 4

• x²+ 4

• 4/x²

• 4x²

Multiple Choice

Write and expression for six less than the quotient of z and 9

• 6 - z/9

• z/9 - 6

• 9z - 6

• 6 - 9z

Multiple Choice

The volume of  a cylinder is  $\Pi$   times the radius squared, multiplied by the height (h). Write an expression for the volume.

•  $\Pi+r\ +h$  

•  $\Pi rh$  

•  $\Pi r^2h$