(x^2)^5÷(x^2)^2
=x^(2*5)÷x^(2*2)
=x^(2*5-2*2)
=x^6
(a^3)^2÷(a^2)^3
=a^(3*2)÷a^(2*3)
=a^6÷a^6
=1
(ab^2)^3÷(-ab)^2
=a^2b^(2*3)÷a^2b^2
=(a^2÷a^2)*b^(2*3-2)
=b^4