Tentukan perkalian bentuk aljabar berikut ini! 1.(3x + 8y) (3x - 8y) 2.(8 + 5y) (9 + 5y) 3.(10 - 3y) (7 + 3y) 4.(5x + 6y)(5x + 6y) 5.(6x - 9y) (6x - 9y) Tolong

1. (3x+8y)*(3x-8y)
= 9x^2-24xy+24xy-64y^2
= 9x^2-64y^2

2. (8+5y)*(9+5y)
= 72+40y+45y+25y^2
= 25y^2+85y+72

3. (10-3y)*(7+3y)
= 70+30y-21y-9y^2
= -9y^2+9y+70

4. (5x+6y)^2
= 25x^2+36y^2+60xy

5. (6x-9y)*(6x-9y)
= 36x^2+81y^2-68xy