How do you combine $\frac { 4u } { u ^ { 2} - 16} + \frac { 2} { u + 7} - \frac { 1} { u + 4}$ ?

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Answer 1 · 2017-04-05T07:46:45

$(5u^2+25u-4)/((u+4)(u-4)(u+7))$

$(4u)/(u^2-16)+(2)/(u+7)-(1)/(u+4)$

$=(4u)/((u+4)(u-4))+(2)/(u+7)-(1)/(u+4)$

$=(4u)/((u+4)(u-4))-(1)/(u+4)+(2)/(u+7)$

$=(4u)/((u+4)(u-4))-(u-4)/((u+4)(u-4))+(2)/(u+7)$

$=(4u-(u-4))/((u+4)(u-4))+2/(u+7)$

$=(3u+4)/((u+4)(u-4))+2/(u+7)$

$=((3u+4)(u+7))/((u+4)(u-4)(u+7))+(2(u-4)(u+4))/((u+7)(u-4)(u+4))$

$=((3u+4)(u+7)+2(u+4)(u-4))/((u+4)(u-4)(u+7))$

$=(3u^2+28+25u+2u^2-32)/((u+4)(u-4)(u+7))$

$=(5u^2+25u-4)/((u+4)(u-4)(u+7))$

How do you combine \frac { 4u } { u ^ { 2} - 16} + \frac { 2} { u + 7} - \frac { 1} { u + 4}\frac { 4u } { u ^ { 2} - 16} + \frac { 2} { u + 7} - \frac { 1} { u + 4}?