2. solution: x? Item: (-3a+2b)x？ * Not including ∴-3a+2b=0∴a=2b/3.

3\, solution: (-4a? )( 12a^4- 16a？ +4a？ )=-48a^6+64a^5- 16x^4

4. Solution: The original formula =(4x? y？ -8xy+4+x？ y？ -4)÷ 1/4xy=(5x？ y？ -8xy)÷ 1/4xy=20xy-32

When x = 2 and y = 1/5, the original formula =20×2× 1/5-32=8-32=-24.

5. Solution: In the product: (2-3m+n)x? 、(2m-3n)x

Not included

∴2-3m+n=0、2m-3n=0

∴m=6/7 n=4/7