Find the slope of the line that contains the ordered pairs. a. (4, 2) and (7, 6.5) b. (10, 8) and (-5, 8) c. (1, -3/4) and (4, -3) d. (18, -7) and (18, 2)

Can any one me with the answers to these questions asap?

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.