tuliskan tanda matematika yg benar

1. (3x + 2y) ^2
= (3x) ^2 + (2 × 3x × 2y) + (2y) ^2
= 9x^2 + 12 xy + 4y^2

2. (2x + 3y) ^4
= (2x) ^4 + (4 × 2x × 3y) + (3y) ^4
= 16 x^4 + 24 xy + 81 y^4