1. ((a²b)/(12c))*((16c)/(ab²))=(16a²bc)/(12cab²)=(4a²b)/(3ab²)=(4a²⁻¹b¹⁻²)/3=(4a)/(3b)
2. (28a)/c³ : (4a²c)=(28a)/c³ * 1/(4a²c)= (7a)/c³ * 1/(a²c)=7/(ac⁴)
3.((6a-6b)/c²)*((4c⁶)/(a²-b²))=(4c⁶(6a-6b))/(c²(a²-b²))=(4c⁶⁻²(6a-6b))/(a²-b²)=(4c⁴*6*(a-b))/((a-b)(a+b))=(4c⁴*6)/(a+b)=(24c⁴)/(a+b)
4. ((5x-10)/(2x+3)) : ((x²-4)/(4x+6))= ((5x-10)(4x+6))/((2x+3)(x²-4))=((5x-10)*2*(2x+3))/((2x+3)(x²-4))=(5*2*(x-2))/((x-2)(x+2))=10/(x+2)
x²-4≠0
x≠±2
2x+3≠0
x≠-3/2