Answer:
n - 13
Step-by-step explanation:
n-4-9
We can combine like terms.
n - (4+9)
n - 13
If it says 3×8 its like saying 8+8+8=21.
It's just a faster way of adding.
Anything multiplied by 0 is 0.
Anything multiplied by 10 just add a 0 to the end of the number example 10×2=20.