Question

Please explain to me

Answer 1

Basically you find the best equation to go with the description like number one

8*n=104+4*n

Answer 2

$\bf \stackrel{\textit{product of a }\stackrel{x}{number}\textit{ and 8}}{8\cdot x}~~=~~\stackrel{\textit{104 more than 4 times that }\stackrel{x}{number}}{4\cdot x+104}\\\\\\~~~~~~~~~~~~~~~~~~~~~~8x=4x+104\\\\-------------------------------\\\\\stackrel{\textit{quotient of a }\stackrel{x}{number}\textit{ and 6}}{\cfrac{x}{6}}~~=~~\stackrel{\textit{15 less than a }\stackrel{x}{number}}{x-15}~~\implies \cfrac{x}{6}=x-15$