Question

Sabendo que log 3 = x e log 5 = y, determine o valor do log 7,5 em função de x e y

Answer 1

$log\,7,5\\\\log\,\left(\frac{3\,.\,5\,.\,5}{10}\right)\\\\Utilizando\;a\;propriedade:\;log\frac{a}{c}=log\,a-log\,c\\\\log\,(3\,.\,5\,.\,5)-log10\\\\Utilizando\;a\;propriedade:\;log\,(a.c)=log\,a+log\,c\\\\(log3+log5+log5)-log10\\\\(x+y+y)-1\\\\x+2y-1$

Resp: x + 2y - 1