Question

Simplify the expression fraction with numerator of the square root of negative twenty five and denominator of the quantity five minus two times i plus the quantity one minus three times i

Answer 1

If I understood you correctly this is the expression we need to simplify:
$\frac{\sqrt{-25}}{(5-2i)+(1-3i)}$
You should keep in mind that square root of -1 is equal to i. i is called the imaginary unit. 
Let us simplify this expression:
$\frac{\sqrt{-1}\cdot \sqrt{25}}{6-5i}= \frac{5i}{6-5i}$
To simplify this further we can multiply numerator and denominator with 6+5i to elimante imaginary numbers from denominator.
$\frac{5i}{6-5i}\cdot \frac{6+5i}{6+5i} = \frac{5i(6+5i)}{6^2-(5i)^2}= \frac{30i-25}{36+25}= \frac{-25+30i}{61}$