Equivalent Expressions

Equivalent Expressions

Part 2

Now that we know 2(3x+2) and 3x+2=7, we can work this out

• 2*(3x+2) means 2*7=14

Now let's use the Associative Property to regroup some other problems.

• 3x+5...We need to rewrite it as 3x+2 +...

Poll

What is the best way I can make 3x+5 into 3x+2

• 3x+1+4

• 3x+5-1

• 3x+2+3

If 2x+5 = 10, then what does 4x+10 equal?

• We are going to first find the gcf/gcd of 4, 10

Multiple Choice

What is the gcd(4, 10)?

• 1

• 2

• 4

• 6

If 2x+5 = 10, then what does 4x+10 equal?

• We know we can factor 4x+10 by pulling out a 2

• 2*(___x+___)

Multiple Choice

4x+10=?

• 4(x+10)

• 10(2/5x+1)

• 2(2x+5)

• 2(x+10)

If 2x+5 = 10, then what does 4x+10 equal?

• If 4x+10=2*(2x+5)

• 2*(2x+5)=2*10=20

If 2x+5 = 10, then what does 2x+20 equal?

• If we factor, it is 2(x+10)...not what we want

• We need to rewrite 20 as a sum of 5 and a number

If 2x+5 = 10, then what does 2x+20 equal?

• So, now 2x+20=2x+5+15

• (2x+5)=10, so (2x+5)+15=10+15=25

If 2x+5 = 10, then what does 2x+1 equal?

• This one is a little tricky?

• So, we need to rewrite 1 with a 5

If 2x+5 = 10, then what does 2x+1 equal?

• Watch....

• 2+1=2x+1+4-4

• When we add in 4 we add in -4, so that it is 0 change

• 2x+5-4=10-4=6

If 2x+5 = 10, then what does -2x-5 equal?

• What is the difference between 2x+5 and -2x-5?

• 
  

• 
  

Poll

What is the difference between 2x+5 and -2x-5

• Different numbers

• Different signs