The result of rolling a number cube 7 times is a 7-digit number composed of digits 1,2,3,4,5 and 6 so that digits can repeat. The total number of possibilities is 6^7.
The number of possibilities where 4 appears exactly two times is 5^5*(7!-6!/2).
5^5 is the number of 5-digits numbers composed of digits 1,2,3,5 and 6 so that digits can repeat.
7! is the number of permutations of digits 1,2,3,4,4,5 and 6.
6! is the number of permutations of digits 1,2,3,{4,4},5 and 6.
We don't want to subtract all numbers where digits 4 appear side by side. That's why we must divide 6! by 2.
Finally, the probability is P=5^5(7!-6!/2)/7^7
7d = 56 minus the x in the middle
Answer:
Step-by-step explanation:
Distributive property: a(b +c) = a*b + a*c
(2x + 1) - 7(-6x + 9) = (2x + 1) + (-7)*(-6x) + (-7)*9
= 2x + 1 + 42x - 63 {Combine like terms}
= 2x + 42x + 1 - 63
= 44x - 62
Answer:
X = 3 x − 14
y = − x + 5
Step-by-step explanation:
Solve for the first variable, then substitute the result into the other equation.
Answer:y=24(2-3)
Step-by-step explanation:
