jawab tolong!! buat besok :( no ngasal yg ngasal/banyak alasan poinnt ny haram jangan lupa pake cara nya

3. (2y-3)(2y+3)
= 4y+6y-6y-9.
=4y-9
4. (3x+8)(3x-8)
= 9x-24x+24x-64
=9x-64
5. (x-3)(x²-2x+5)
= x³-2x²+5x-3x²+6x-15
=x³+((-2)-3))x²+(5+6)x-15
=x³-5x²+11x-15
jawabanku sih gini...