I need help with this basic Algebra 1 problem

Here is the problem:

5-4x+2x^2+7-x

I understand your supposed to add the like terms, but I keep getting the wrong answer here. The correct answer is 2x2 – 5x + 12, but I have no clue how they got there, because I think I keep messing up the order. I thought you added/subtracted like terms first, so the problem would work out to: 5-6x^+7-x. Now I'm lost there. :(

5-4x+2x^2+7-x

Rearranging to group like terms (make certain you keep the signs correct)
5 + 7 - 4x - x + 2x^2
12 - 5x + 2x^2

Jim

Like terms

(5 + 7) + (-4x - x) + 2x²

2x² - 5x + 12

----I hope this clears things up ( a + 2a = 3a (like) but a + 2a² are not like and cannot be added)

Edited 8 seconds ago
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Jim Jim
5-4x+2x^2+7-x

Rearranging to group like terms (make certain you keep the signs correct)
5 + 7 - 4x - x + 2x^2
12 - 5x + 2x^2

Jim
Source(s):
BS Computer Science

22 seconds ago
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JOS J JOS J
5 - 4 x + 2 x^2 + 7 - x

(5 + 7) + (-x - 4 x) + (2 x^2)

12 - 5 x + 2 x^2

7 seconds ago
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5-4x+2x^2+7-x

2x^2 - 4x - x + 5 + 7

2x^2 - 5x + 12

Like terms

(5 + 7) + (-4x - x) + 2x²

2x² - 5x + 12

----I hope this clears things up ( a + 2a = 3a (like) but a + 2a² are not like and cannot be added)

You add the coefficients of similar power terms, so:
2x^2=2x^2 only one term,
-4x-x = -5x
5+7=12
thus:
2x^2-5x+12

5 - 4 x + 2 x^2 + 7 - x

(5 + 7) + (-x - 4 x) + (2 x^2)

12 - 5 x + 2 x^2

5-4x+2x^2+7-x

2x^2 - 4x - x + 5 + 7

2x^2 - 5x + 12

12-5x+2X^2