[15] MaTHS QuesTion =] 要列steps.. thx :)

do u want to factorize the polynomials?
if yes, here is the solution.

1. 16a^2 + 8a + 1
=(4a)^2 + 2(4a)(1) + (1)^2
=(4a+1)^2

2. 9s^2 + 6s + 1
=(3s)^2 + 2(3s) + (1)^2
=(3s+1)^2

3. 4+12n+9n^2
=(2)^2+2(2)(3n)+(3n)^2
=(2+3n)^2

4. 16u^2-72uv+81v^2
=(4u)^2-2(4u)(9v)+(9v)^2
=(4u-9v)^2

5. 80r^2+40rs+5s^2
=5(16r^2+8rs+s^2)
=5[(4r)^2+2(4r)(s)+(s)^2]
=5(4r+s)^2

6. 4(x-y)^2-4z(x-y)+z^2
=[2(x-y)]^2-2[2(x-y)](z)+(z)^2
=[2(x-y)+z]^2
=(2x-2y+z)^2

7. 1-6t^2+9t^4
=(1)^2-2(1)(3t^2)+(3t^2)^2
=(1-3t^2)^2

8. 1-6t^2+9t^4-121s^2
=(1)^2-2(1)(3t^2)+(3t^2)^2-(11s)^2
=(1-3t^2)^2-(11s)^2
=[(1-3t^2)-(11s)][(1-3t^2)+(11s)]
=(1-3t^2-11s)(1-3t^2+11s)