Question

aflati numitorup comun al lui 1/270+1/405+1/360

Answer 1

$270 = 9\times30 = 3\times3\times3\times10 = 3^3\times2\times5 = 2\times3^3\times 5\\ \\ 405 = 5\times 81 = 5\times 3^4 = 3^4\times 5 \\ \\ 360 = 4\times 60 = 2^2\times 3\times 2\times 10 = 2^3\times 3\times 2\times 5 = 2^4\times 3\times 5\\ \\ \\ cmmmc (270,405,360) = 2^4\times 3^3\times 5 = 2160\\ \\ \\ \Rightarrow Numitorul comun este 2160.$