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23 votes
Which step gives an incorrect property or reason in the process of solving the equation?

-4(3x+6) +6=-30

-12x-12+6=-30 by the distributive property (Step 1)

-12x -6=-30 by the Commutative Property (Step 2)

-12x -6+6 = -30 +6 Addition (Step 3)

-12x +0 = -24 Additive inverse & Substitution (Step 4)

-12x = -24 Additive Identity (Step 5)

x = 2 Division (Step 6)

User Lukaswelte
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2 Answers

22 votes
22 votes

Answer: Step 1 is solved incorrectly.

Step-by-step explanation:

-4(3x+6) +6=-30

= -12x-24+6=-30

and not

-12x-12+6=-30.

The real solution is x=1. Here is how:

−4(3x+6)+6=−30

Use the distributive property to multiply −4 by 3x+6.

−12x−24+6=−30

Add −24 and 6 to get −18.

−12x−18=−30

Add 18 to both sides.

−12x=−30+18

Add −30 and 18 to get −12.

−12x=−12

Divide both sides by −12.

x=−12−12​

Divide −12 by −12 to get 1.

x=1

Hope this helped!

User AlfredoCasado
by
3.1k points
27 votes
27 votes

Answer:

addition is the answer because all of the other equations will have the same x value

User Umutm
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2.8k points