Question

( this is sum by gcf ) 15+81= __ (__+__)? what is the gcf of 15 and 81

Answer 1

$15+81=3(5+27) \to 3*32 =\boxed{96} \\\\ 15|3 \\ 5 \ |5 \\ 1 \\\\15=3*5 \\\\\\ 81|3 \\ 27|3 \\ 9 \ |3 \\ 3 \ |3 \\ 1 \\\\ 81=3^4 \\\\ G.C.F(15;81)=3$

Answer 2

$15+81=3\cdot5+3\cdot27=3(5+27)$