For this case we must add the terms of the following expression:
[tex]6y \sqrt {a} + 7y \sqrt {a}[/tex]
It is noted that the terms are similar, so we can add:
We take common factor [tex]\sqrt {a}:[/tex]
[tex]\sqrt {a} (6y + 7y) =[/tex]
We add the terms within the parenthesis:
[tex]\sqrt {a} (13y) =[/tex]
finally we have:
[tex]13y \sqrt {a}[/tex]
Answer:
[tex]13y \sqrt {a}[/tex]
