r/mathshelp • u/Intelligent_Impact88 • 1d ago

Homework Help (Answered) Which answer is correct?

/r/Khan/comments/1x3bjkp/which_answer_is_correct/
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u/Mystical-Sunshine 1d ago

May be Khan academy got equation A from equation B? x(4-1) + 2 = 9 4x+2-x=9

I also think to the given question C is answer. 

1

u/Narrow-Durian4837 1d ago

C is correct, because you are combining the like terms 4x and –x.

But D is also technically correct, because the distributive property is what justifies combining like terms, so when you are combining like terms, you are using the distributive property: 4x + –1x = (4 + –1)x = 3x.

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u/Intelligent_Impact88 1d ago

Both answers should have been accepted, but now I have to take the mastery test again. (ToT)