Permutations and combination question How many arrangements of four digit numbers can be made using the numbers 2 through 9 if no numbers can be repeated?

a) 840

b) 504

c) 1680

d) 4096

Step-by-step explanation:

2,3,4,5,6,7,8,9 = 8 números diferentes

ce pula mea vrei ma

step-by-step explanation:

gayule

option 2 is correct.

step-by-step explanation:

we are given two inequality equation

x+y> 5 and -3x+2y< -2

first we draw the graph of both function using t-table method

equation: x+y> 5

for x=0, y=5

for x=-5, y=0

table:

x   :   0     5

y   :   5     0

test point (0,0) , 0> 5

false

equation: -3x+2y< -2

for x=0, y=-1

for x=2, y=4

table:

x   :   0     2

y   : -1       4

test point (0,0) , 0< -2

true

now we draw the graph. see the attachment for graph.

common region would be solution set.

option 2 is correct.