Question 881780
The denominators are NOT the same. So you CANNOT add the fractions yet.



You must make the denominators equal to the same expression so you can add the fractions. 



The first denominator is x+1 and the second denominator is x^2+x=x(x+1)



Notice how the first denominator is missing an x out front



So we multiply top and bottom of the first fraction by x 



After doing this, we can finally add the fractions



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{{{4/(x+1) + (3x)/(x^2+x)}}}



{{{4/(x+1) + (3x)/(x(x+1))}}} Factor the second denominator.



{{{(red(x)*4)/(red(x)(x+1)) + (3x)/(x(x+1))}}} multiply top and bottom of the first fraction by x



{{{(4x)/(x(x+1)) + (3x)/(x(x+1))}}}



{{{(4x+3x)/(x(x+1))}}} The denominators are finally the same, so we add the numerators over the LCD.



{{{(7x)/(x(x+1))}}}



{{{(7*highlight(x))/(highlight(x)(x+1))}}}



{{{(7*cross(x))/(cross(x)(x+1))}}}



{{{(7)/(x+1)}}}



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So {{{4/(x+1) + (3x)/(x^2+x)}}} simplifies to {{{(7)/(x+1)}}}



So you were close.