Respuesta :
cross multiply
10 x 9 = 90
3 x k = 3k
make an equality
90 = 3k
divide both sides by 3
90/3 = k
simplify
30 = k
10 x 9 = 90
3 x k = 3k
make an equality
90 = 3k
divide both sides by 3
90/3 = k
simplify
30 = k