Answer:
The sum of coefficients = 9 
Explanation:
The given expression is, 
 3x⁴ + 5x² + x 
There are three terms in the given expression. All the terms contains variable x. 
To find the coefficients of each terms 
term coefficients 
 3x⁴ 3 
 5x² 5 
 x 1 
To find the sum of coefficients 
sum = 3 + 5 + 1 = 9 
Therefore the sum of coefficients = 9