Distributive Property Slides Review-Lisi

Distributie Property

How it works

Poll

Before we start, how do you feel about the distributive property?

• It's confusing

• I kind of get it

• I get it, but sometimes I make mistakes

• I already know this but it never hurts to review!

Example: How it works

2(3+x)

=2⋅(3+x) "Multiplying by 2 means add two times!"

=(3+x)+(3+x) "We add (3+x) two times"

=3+x+3+x "Drop the parentheses"

=3+3+x+x "regroup"

=6+2x "Combine like terms"

That was too much work, there must be an easier way!

Short cut: Multiply everything inside the parentheses by the number in front!

2(3+x)

=2⋅(3+x)

=2⋅3+2⋅x

=6+2x

Multiple Choice

Which expression shows the distributive property applied correctly to 3(x+7)

• 3⋅x+7

• x+3⋅7

• 3⋅x + 3⋅7

Multiple Choice

Simplify 3(x+7) using the distributive property

• 3x+7

• 3x+21

• x+21

When applying the distributive property, watch out for the signs! Follow these rules for signs when multiplying:

• (+)(+) = +

• (+)(-) = -

• (-)(+) = -

• (-)(-) = -

Example 1: Use distributive property to simplify 3(5-x)

Be sure to distribute the 3 to both terms and watch the signs!

3(5-x)

=3⋅(5-x)

=3⋅5+3⋅-x

=15+(3⋅-1)x

=15-3x

Multiple Choice

Use distributive property to simplify 5(7-x).

Be sure to distribute the 5 to both terms AND watch the signs!

• 35 - x

• 35 + 5x

• 35 - 5x

Multiple Choice

Use distributive property to simplify 5(-7+x).

Be sure to distribute the 5 to both terms AND watch the signs!

• 35 + 5x

• -35 + 5x

• 7 + 5x

Example 2: Use distributive property to simplify -3(5-x)

Be sure to distribute the -3 to both terms and watch the signs!

-3(5-x)

=-3⋅(5-x)

=-3⋅5+-3⋅-x

=-15+(-3⋅-1)x

=-15+3x

Example 3: Use distributive property to simplify -7(-5+x)

Be sure to distribute the -7 to both terms and watch the signs!

-7(-5+x)

= -7⋅(-5+x)

= -7⋅-5 + -7⋅+ x

= +35 + (-7⋅+1) x

=35 - 7x

Multiple Choice

Choose the option that shows the correct signs after applying the distributive property for

-3(-x-5)

Check the signs!

• -3x - 15

• 3x - 15

• 3x + 15

Multiple Choice

Use the distributive property to simplify

-4(x-2)

Watch out for the signs!

• -4x + 8

• 4x - 8

• -4x - 8

Poll

How do you feel after completing this Quizizz?

• More confused than before!

• No change, I still don't get it

• I think I get it now!

• I already knew this, but it never hurts to review!