To log on to a certain computer account, the user must type in a 4-letter password. In such a password, no letter may be repeated, and only the lower case of a letter may be used. How many such 4-letter passwords are possible

 358800

Step-by-step explanation:

To create a four-letter password such that no letter are repeated and only lower cases are used;

For the first letter, we can choose any letter from A to Z = 26

We can choose any letter from A to Z except for the first letter for the second letter. = 25

We can choose any letter from A to Z except for the first & second letter for the third letter. = 24

We can choose any letter from A to Z except for the first, second & third letters for the fourth letter. = 23

SO;

No of ways in which 4-letter passwords are possible = 26 × 25 × 24 × 23

No of ways in which 4-letter passwords are possible =  358800

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

step-by-step explanation:

if you meant, "on the way from (3, 2) to (3, 14):

x does not change; y increases by 12.

ensure that you have copied down this problem correctly.   .