<PRE><B>Question 153340</B>
1. (5x^2-7x+2)-(8-4x)


Distribute the -:
5x^2-7x+2-8+4x


Combine like terms
5x^2-3x-6
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2. If 12/x+4 = (2+ x)/x+4:


Cancel the denominators
12=2+x


Subtract 2 from both sides
10=x
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If 12/x+4=2/1 + x/x+4:


Subtract x/x+4 from both sides
12-x/x+4=2/1


Cross multiply
12-x=2(x+4)


Distribute
12-x=2x+8


Add x to both sides
12=3x+8


Subtract 8 from both sides
4=3x


Divide both sides by 3
4/3=x
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