I JUST TOOK THE TEST AND THE ANSWER IS D
Answer:
504 combos
Step-by-step explanation:
Cannot use digits twice and last is '7'
9 digits for first place choice
8 digits for second place
7 digits for third place
only '7' for fourth place 9 x 8 x7 = 504 combos
16z because you’re adding 4z four times
Answer:

Step-by-step explanation:
We want to simplify:

Recall the Pythagorean Identity:

So:

Substitute:

Factor. We can use the difference of two squares pattern:

Cancel. Hence:
