1. a²-6a+9
4x²+4xy+y²
25b²-9y²
2. 4a²-8a-a²+8a+16=3a²+16
2(x²+2x+1)-4x=2x²+4x+2-4x=2x²+2
3. (x-5)(x+5)
a(x-c)(x+c)
4. (a-16)+(a²-16)+8a=( -0.3-16)+((-0.3)²-16)+8•(-0.3)= -16.3-15.91-2,4= -34,61
5. (x²-3x)+(-y²-3y)=x(x-3)-y(y+3)
25x²-x²-6x-9=24x²-6x-9
16x⁴-81=(4x²-9)(4x²+9)