Answer:
4x^2 - 28x
Step-by-step explanation:
area = length * width
a = 4x * (x-7)
4x^2 - 28x
Step 1a. For a card number with an even number of digits (e.g., Visa or MasterCard), double alternating digits starting with the first digit in the sequence.
Step 1b. For a card with an odd number of digits (e.g., American Express), double alternating digits starting with the second digit in the sequence.
Step 2. If the doubling resulted in a number with two digits, add them together to get a single digit number
Step 3. Now go back to the original credit number and replace the digits that you doubled with the new value — either the doubled value, or the doubled value with the digits added together — and add it all up.
Step 4. Check to see if the sum is evenly divisible by 10 (you can simply look to see whether or not it ends with a zero).
If the card number does not pass this check, then it is not a valid number. If, on the other hand, it does pass, then it may be a valid number with valid credit report.
9514 1404 393
Answer:
5x -3y = 44
Step-by-step explanation:
We choose to start with the form ...
(Δy)x -(Δx)y = (Δy)(x1) -(Δx)(y1) . . . . . where Δy = y2 -y1 and Δx = x2 -x1
For this purpose, it is convenient to choose y2 > y1, so we have ...
Δy = -3 -(-8) = 5
Δx = 7 -4 = 3
5x -3y = 5(4) -3(-8)
5x -3y = 44
3a - 4b = 21
check (-2 , -3)
3(-2) -4(-3) =21
-6 +12 = 21
6 does not = 21 so NO
check (0 , 7)
3(0) -4(7) =21
0-28=21
-28 does not equal 21 so NO
check (-3 , -2)
3(-3) -4(-2) =21
-9 +8 = 21
1 does not = 21 so NO
check (7 , 0)
3(7) -4(0) =21
21 = 21
Choice D
Answer:
i think b
Step-by-step explanation: