Ответ............................
1. (12c-10)(12c+10)
2. (7x-9y)(7x+9y)
3. (1.1m³ - 0.2m²)(1.1m³ + 0.2m²)
4. (a+10-4)(a²+20a+100+4a+40+16)=(a+6)(a²+24a+156)
5. (4a+5)(16a²-20a+25)
1) Тк 15^0=1.
3^(2/3) * 3^5 * 3^(-6) *3^(1/3)=
=3^(2/3 +5-6+1/3)=3^0=1
2) Тк sqrt(16)=4,то получим:8^(2/3)=4