Hello.
First of all, let the number be t.
8 times t can be written like this:

Notice that the number is before the variable and the times sign (×) is not there.
We can write it as 8×t, but we usually write it as 8t.
The sum of means we add:
8t+21
Now, "less than" is "<" :

Therefore, the answer is

I hope it helps.
Have a nice day.

Commutative property of multiplication is two numbers being multiplied either way,example 1x2 = 2x1.
Answer:
I do not understand very well but they are already helping me
Answer:
- 40
Step-by-step explanation:
The absolute value always returns a positive value , that is
- | - 40 | = - | 40 | = - 40