15y + (x + 9y)
First, simplify. / Your problem should look like: [tex]15y + x + 9y[/tex]
Second, gather the like terms. / Your problem should look like: [tex](15y + 9y) + x[/tex]
Third, simplify. / Your problem should look like: [tex]24y + x[/tex]
Answer: 24y + x
