If i have been given 5x + 7x+ 8 which is the constant term?

$5 x , 7 x \mathmr{and} 8$
The values of $5 x \mathmr{and} 7 x$ might change depending on the value that $x$ will take. But the value of 8 will always be 8, irrespective of the value of $x$
Hence, the constant term in $5 x + 7 x + 8$ is $\textcolor{g r e e n}{8}$