Answer:
it's E
Step-by-step explanation:
(5x+y)²
You expand the bracket
it gives;
(5x + y)(5x+y)
Now, multiply 5x by 5x=25x²
multiply 5x by y= 5xy
multiply y by 5x=5xy
multiply y by y=y²
Bringing into an equation it gives;
25x²+5xy+5xy+y²
=25x²+10xy+y²
