Your answer will be [tex] x^{2} -2xy- 15y^{2} [/tex]
To get this you have to multiply individually across the parenthesis. Like so:
x(x+3y)
↓
[tex] x^{2} +3xy[/tex]
-5y(x+3y)
↓
[tex] -5xy-15y^{2} [/tex]
Now we add these two expressions together: [tex] x^{2} +3xy[/tex] + [tex] -5xy-15y^{2} [/tex]
Next, we combine like terms: [tex] x^{2} -2xy- 15y^{2} [/tex]
Since nothing else can be simplified, this is our answer. Hope this helped!!!
