Answer:
25y^2 -20iy + 4i^2
Explanation:
Theres an acronymn called Foil (first, ouside, inside, last) for expanding an expression like that
For this expression:
= (5y - 2i) (5y - 2i)
= 25y^2 - 10iy - 10iy + 4i^2
= 25y^2 -20iy + 4i^2
This is assuming that "i" is not the imaginary number "i"