Answer:
X = {0, 1, 2, 3, 4}
Step-by-step explanation:
If X is the number of nonzero digits in a 4-digit PIN with no restriction on the digits, the pin can have up to 4 nonzero digits.
Let's see some examples:
If the PIN is 0000 then X = 4
If the PIN is 2045 then X = 3
If the PIN is 7546 then X = 0
From the previous examples, we can see that the possible values for X are 0, 1, 2, 3, 4.
Thus X = {0, 1, 2, 3, 4}
The answer is 15w^2 + 225w
Key:
^ - Means that it is an exponent, in case you didn't know :)
Answer: x^2 + 9x + 20
Step-by-step explanation:
Foil Method: (a + b) (c + d) = ac + ad + bc + bd
Lets say:
a = x
b = 5
c = x
d = 4
Plugging in the numbers: xx + 4x + 5x + 5*4
Combine like terms:
xx = x^2
4x + 5x = 9x
5 * 4 = 20
You're then left with: x^2 + 9x + 20
Answer. NOOOOOO
Step-by-step explanation:
