Answer:
The solution of this expression is
and
.
Step-by-step explanation:
The procedure for solution of exercise A is described below:
1) We expand the expression.
2) The resulting expression is rearranged into the form of a second order polynomial.
3) Roots are found by Quadratic Formula.
Step 1:



Step 2:

Step 3:



The solution of this expression is
and
.
visa cards begin with 4 and then have 13 or 16 digits but here we have a number beginning with 4 and then it has the 15 digits.
<u>Step-by-step explanation:</u>
- Each card has a different first digit number. The maximum length of this type of credit card number can be up to 19 digits.
- In the visa card starting 6 digits are always said to be the issuer identifier.
- The visa cards will have the starting digits as 4 whereas in Mastercard the starting digit is 5 but it has 16 digits numbers.