Answer:
d
Step-by-step explanation:
Slope intercept form: y = mx + b
y = -x + 7
x + y = 21
x + y = 21
-x -x
y = -x + 21
y = -x + 7
y = -x + 21
Parallel lines have the same slope. Here, our slope is -1
Therefore, our final answer is d.
Hope this helps!
Answer:

Step-by-step explanation:
In this question, you would solve for "a".
Solve:
K = 4a + 9ab
Since we have our "a" on the same side, we can factor it out from the variables:
K = a(9b + 4)
To get "a" by itself, we would have to divide both sides by 9b + 4:
K/9b+ 4 = a
Your answer would be K/9b+ 4 = a
It would look like this: 
Answer:
$308.50
Step-by-step explanation:
3702 ÷ 12 = 308.5 is her monthly payment
First, there are 26 distinct alphabets and 10 distinct digit numbers.
Then, the first digit of ID has 26 possibilities.
For the rest of 2 digits, the total cases are 10*10 = 100 possibilities.
However, there are 10 cases are repeated when two digits are the same. so you have to subtract it by 10
So answer will be 26 * (100-10) = 23400