aˣ/aʸ = aˣ⁻ʸ
For (16a⁴/12a³)], you can separate out the numbers and the variable so you get:
16/12 times a⁴/a³.
Think of 16/12 as a fraction and reduce it to its lowest terms --> 4/3
Same for a⁴/a³ --> a⁴⁻³ --> a
Put them back together and you get 4a/3
For [(40a^2/12a^3)], separate to 40/12 times a²/a³.
40/12 --> 10/3
a²/a³ --> a²⁻³ --> a⁻¹ --> 1/a
Put them together --> 10/3a
For [(24a/12a^3)], separate to 24/12 times a/a³.
24/12 --> 2
a/a³ --> a¹⁻³ --> a⁻² --> 1/a²
Put them together --> 2/a²
So, we get
(4a/3) - (10/3a) + (2/a²)
We can make it neater by keeping the denominators the same. The LCM is 3a².
Multiply 4a/3 by a²/a² to get 4a³/3a².
Multiply 10/3a by a/a to get 10a/3a².
Multiply 2/a² by 3/3 to get 6/3a².
Now, we can turn the expression into a single fraction.
(4a³/3a²) - (10a/3a²) + (6/3a²) --> (4a³-10a+6)/(3a²)