Answer:
[tex]3(5+x)=15+3x[/tex], first option
Step-by-step explanation:
The distributive property lets us multiply a parentheses by its coefficient. For example:
[tex]4(x+3)=[/tex]
[tex]4*x + 3*4=[/tex]
[tex]4x+12[/tex]
Apply this theory to this problem.
[tex]3(5+x) =[/tex]
[tex]3*5+3*x=[/tex]
[tex]15+3x[/tex]
Thus, the answer is the first option, [tex]3(5+x)=15+3x[/tex]