2b²分之5a²×a分之2b
=5a²/2b²×2b/a
=5a/b
2y分之x²×3x分之4y²
=x²/2y×4y²/3x
=2xy/3
﹙ab－b²﹚×ab分之a－b
=b(a-b)×(a-b)/ab
=(a-b)²/a
m²＋4m＋4分之m²－4×m－2分之m²²＋2m.
=(m+2)(m-2)/(m+2)²×m(m+2)/(m-2)
=1/m
4分之a²－1×a－1分之6a
=(a+1)(a-1)/4×6a/(a-1)
=3a(a+1)/2
b²分之2a－b××3x分之4y²
=(2a-b)/b²×4y²/3x
=4(2a-b)y²/3b²x