Question 643773
<pre>
 5rｲ + 40r + 75
覧覧覧覧覧覧覧覧
25rｲ - 50r - 375

Factor the numerator:

 5rｲ + 40r + 75 =

Factor out 5

 5(rｲ + 8r + 15) <-- SIMPLIFIED NUMERATOR

Factor the trinomial in the parentheses:

 5(r + 5)(r + 3)

Factor the denominator:

25rｲ - 50r - 375

Factor out 25

25(rｲ - 2r - 15)

Factor the trinomial in the parentheses:

25(r - 5)(r + 3) <-- SIMPLIFIED DENOMINATOR

So putting the simplified numerator over 
the simplified denominator we have:

{{{(5(r + 5)(r + 3))/(25(r - 5)(r + 3))}}}

cancel the (r+3)'s

{{{(5(r + 5)(cross(r + 3)))/(25(r - 5)(cross(r + 3)))}}}

{{{(5(r + 5))/(25(r - 5))}}}

Divide top and bottom by 5:

{{{(r + 5)/(5(r - 5))}}}

Edwin</pre>