Question 1103231
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Please use parentheses where required to make the problem clear....!!<br>
I assume the expression is supposed to be
{{{((x^2+2z-15)/(x+4))/((5x^2+25x)/(x+4))}}}<br>
With the "x+4" in both denominators, we can essentially ignore them.  (Or, if you prefer, we can multiply numerator and denominator of the original fraction by (x+4).)<br>
We end up with
{{{(x^2+2z-15)/(5x^2+25x)}}}<br>
Here both the numerator and denominator factor easily; and the expression can then be simplified by canceling common factors.<br>
That part should be easy; I'll leave it for you to finish.