Discussion

If 3x + 9 = 15, then x + 2 =

(A)2
(B)...
(C)...
(D)...
(E)...
(F)...
*This question is included in Nova Math - Diagnostic: Test / Review, question #1

The solution is

Posted: 12/28/2011 07:39
How is the answer not 2 X+3=5 x is definitely 2.
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Contributor
Posted: 12/28/2011 14:04
Matt, you are right that x is 2; however the question asks for x+2, so the answer is 4 (C). You have to be careful in the test because sometimes the question writer is sneaky like that.
Posted: 01/03/2012 14:08
How do you get 4 if you divide 9 by3 wouldn't the answer be 3?
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Contributor
Posted: 01/03/2012 22:10
Joceline, dividing both sides of the equation by 3 gives you x + 3 = 5. We are solving for x, which is 2. then x + 2 = 4.
Posted: 01/29/2012 17:00
Where does the one come from
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Contributor
Posted: 01/30/2012 00:14
Camerin, I would say: "From heaven" or "Outside the Matrix" but that's me be being funny, since I am not sure which 'one' you refer to.

The question however requires you to first solve:
3x + 9 = 15
Subtract 9 from both sides
3x = 6
Divide both sides by 3
1x = 2
x = 2
This make the question
If x = 2 then x + 2 = 2 + 2 = 4

Another way would be;
3x + 9 = 15
Since each factor is a multiple of three, we divide each factor by 3
1x + 3 = 5
Subtract 3 from both sides
1x = 2
x = 2
x + 2 = 2 + 2 = 4

The only 'one' we have is in 1x which is the coefficient of variable x and though we know each variable has a coefficient we tend to omit it when it's equal to 1 since anything times 1 remain the same value.

Niels
Posted: 09/19/2012 00:37
Do u have any other way to do that

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Contributor
Posted: 09/19/2012 17:50
Walid,
3x + 9 = 15, to start;
3 (x+3) = 15, by factoring out 3 on the left side;
x + 3 = 5, after dividing by 3 on both sides;
x + 2 = 4, after subtracting by 1 on both sides.
Posted: 12/04/2012 15:45
The answer is (C).
Posted: 10/13/2014 12:22
Reply: no it's noooooot
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Admin
Posted: 05/05/2015 18:12
Test post
Posted: 06/08/2015 07:04
Reply: yeah

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