Question

Nathan wrote the following steps to prove the equation:
Given: 3(x + 2) = 6x + 3
Prove: x = 1

Step Mathematical Statement Justification
0 3(x + 2) = 6x + 3 Given
1 3x + 6 = 6x + 3 Distributive Property
2 6 = 3x + 3 Commutative Property of Addition
3 3x + 3 = 6 Symmetric Property of Equality
4 3x = 3 Subtraction Property of Equality
5 x =1 Division Property of Equality

Which step of justification is incorrect, and what should the justification for that step be to solve the equation?

Answer 1

The answers:
Step 4; Commutative Property of Multiplication
Step 1; Associative Property of Addition
Step 2; Subtraction Property of Equality
Step 3; Reflexive Property of Equality

Answer 2

Could you help me?

Answer 3

the key is knowing all of those properties...
How is step 2 obtained from step 1? Definitely not commutative propert....

Answer 4

you have to do addition before subtraction right?

Answer 5

Leaving doesn't help me learn, can someone else please help me?

Answer 6

What else dpalnc, was I right about that?

Answer 7

about leaving?

Answer 8

I was wrong, but it had said you left, I apologize for my false assumptions.

Answer 9

Can you still help me?

Answer 10

step1: 3x + 6 = 6x + 3
step2: 6 = 3x + 3

notice to get from step 1 to step 2 you'd have to subtract 3x from both sides of the equal sign... so

3x + 6 -3x = 6x + 3 -3x
6 = 3x + 3
this is what step 2 is.... so the property used is subtraction property of equality...
just a fancy way of saying "subtract the same amount on both sides of the equal sign"

Answer 11

So the answer is 3 then?

Answer 12

the third choice on your list...

Answer 13

I mean the third answer of the four given.

Answer 14

yes, would you like to help me with one more now that I understand that one?

Answer 15

sure... just post it up and close this one... :)

Answer 16

alirght