Answer:
2(6y + 3)
Explanation:
for the equation to have infinitely many solutions, then both sides must be equal.
consider left side
5y + 6 + 7y ← collect like terms
= 12y + 6 ← factor out 2 from each term )
= 2(6y + 3)
then
5y + 6 + 7y = 2(6y + 3) ← has infinitely many solutions