Объяснение:
3/m + 5/n=(3n+5m)/(mn)
4/x - 3/xy=(4y-3)/(xy)
7/9ab - 13/12ab=(4·7-3·13)/(36ab)=(28-39)/(36ab)=-11/(36ab)
6p/5xy + 4k/3xy² - 3m/4x²y=(12xy·6p+20x·4k-15y·3m)/(60x²y²)=(72xyp+80xk-45ym)/(60x²y²)
2n-5m/n + (6n²+5m²)/mn=(m(2n-5m)+6n²+5m²)/(mn)=(2mn-5m²+6n²+5m²)(mn)=(2mn+6n²)/(mn)=2n(m+3n)/(mn)=2(m+3n)/m, при упрощении (2m+6n)/m
6x²-3x+2/x²y - 3x-2/xy=(6x²-3x+2-x(3x-2))/(x²y)=(6x²-3x+2-3x²+2x)/(x²y)=(3x²-x+2)/(x²y)
Объяснение:
3/m + 5/n=(3n+5m)/(mn)
4/x - 3/xy=(4y-3)/(xy)
7/9ab - 13/12ab=(4·7-3·13)/(36ab)=(28-39)/(36ab)=-11/(36ab)
6p/5xy + 4k/3xy² - 3m/4x²y=(12xy·6p+20x·4k-15y·3m)/(60x²y²)=(72xyp+80xk-45ym)/(60x²y²)
2n-5m/n + (6n²+5m²)/mn=(m(2n-5m)+6n²+5m²)/(mn)=(2mn-5m²+6n²+5m²)(mn)=(2mn+6n²)/(mn)=2n(m+3n)/(mn)=2(m+3n)/m, при упрощении (2m+6n)/m
6x²-3x+2/x²y - 3x-2/xy=(6x²-3x+2-x(3x-2))/(x²y)=(6x²-3x+2-3x²+2x)/(x²y)=(3x²-x+2)/(x²y)