①25x²-36
=(5x+6)(5x-6
②64-16a²
=16(4-a^2)
=16(2+a)(2-a)
③0.49x²-0.04y²
=(0.7x+0.2y)(0.7x-0.2y)
④-4a²b²+4ab-1
=-(4a²b²-4ab+1)
=-(2ab+1)^2
①25x²-36
=(5x+6)(5x-6
②64-16a²
=16(4-a^2)
=16(2+a)(2-a)
③0.49x²-0.04y²
=(0.7x+0.2y)(0.7x-0.2y)
④-4a²b²+4ab-1
=-(4a²b²-4ab+1)
=-(2ab+1)^2