25^2*5^5/5^7=25^2/5^2=5^2*5^2/5^2=5^2=25
(x-3)(x+5)(x+3)(x-5)=(x^2+2x-15)*(x+3)*(x-5)=(x^3+5x^2-9x-45)*(x-5)=(x^2-9)(x^2-25)=x^4-34x^2+225
1) 1/64*32²=16
3)2⁻¹/2⁻¹²=2¹¹=2048
2) 6⁶:6¹⁰=1/1296
4)3⁻²/3⁶=3⁻⁸=1/6561