Answer:
[tex]\huge\boxed{\sf 5y^2 -4}[/tex]
Step-by-step explanation:
[tex]\sf (7y^2 + 3xy -9) - (2y^2+3xy-5)\\\\Resolving \ Parenthesis\\\\7y^2 + 3xy-9 -2y^2 -2xy+5\\\\Combining \ like \ terms\\\\7y^2-2y^2+3xy-3xy-9+5\\\\Adding \ or \ Subtracting\\\\\boxed{\bold{\sf 5y^2-4}}[/tex]
