Question

представьте в виде дроби

Answer 1

a) 
$frac{3x-1}{x^2} + frac{x-9}{3x} = frac{3(3x-1) + x(x-9)}{3x^2} = frac{9x-3+x^2-9x}{3x^2} = frac{x^2-3}{3x^2}$

б)
$frac{5}{c+5} - frac{5c-2}{c^2+3c} = frac{5}{c+5} - frac{5c-2}{c(c+3)} = frac{5c(c+3) -(5c-2)(c+5) }{c(c+3)(c+5)} = \ \ = frac{5c^2+15c - (5c^2+25c- 2c-10)}{c(c+3)(c+5)} = frac{5c^2+15c -5c^2-23c+10}{c(c+3)(c+5)} = \ \ = frac{10-8c}{c(c^2+8c+15)} = frac{10-8c}{c^3+8c^2+15c}$