(-14x³)/(x³ - 5x^4)
factor out x³ from the numerator (top) and also from the denominator (bottom):
-14 (x³) / (1-5x)(x³)
cancel out the common factor of x³:
-14/(1-5x)
Do the same process for the second question (but factor out x):
x/(4x + x²) = 1/(4+x)