3n/2-n/4=7n+4/12
12 (3n/2-n/4=7n+4/12) factored in 12 to both sides to get rid of fractions
12 (3n/2)-12 (n/4)=12 (7n)+12 (4/12) distributive power
36/2n-12/4n=84n+48/12
18n-3n=84n+4 simplified
15n=84n+4
15n-84n=84n-84n+4 addition property
-69n=4
-69/-69n=-4/69 division property
n=-4/69
Solution : n=-4/69
Answer:
-40
Step-by-step explanation:
Work backwards
4 * -7 = -28
-28 - 12 = -40
The number of ways to select 4 digits from 10 digits is
₁₀C₄ = 10!/(4!*6!)
= (10*9*8*7*6!)/(4*3*2*1*6!)
= (10*9*8*7)/(4*3*2)
= 210
If order is not important, the number of arrangements of 6,7,8,9 in any order is
4! = 4*3*2*1
= 24
The probability that these 4 digits are assigned is
24/210 = 0.1143
