Let x be the set of the 26 lowercase english letters and 10 decimal digits. how many x-strings of length 15 satisfy all of the following properties (at the same time)?

a. the first and last symbols of the string are distinct digits (which may appear elsewhere in the string).
b. precisely four of the symbols in the string are the letter ’t’.
c. precisely three characters in the string are elements of the set v fa; e; i; o; ug and these characters are all distinct.

hc ghfrfgb

step-by-step explanation:

gedfgb nbgfrezrdfgbn bgfderdfgbvn bvfdsvcb bvfdfgb gfdgb gfr

show da graph

step-by-step explanation:

the answer to this in exact form is 4/35 but in decimal form its 0.1142857

hope this if needed hmu

x^2 + 81

we can factor this using difference of square binomials.

rewrite the equation:

x^2 - (-81)

factor:

(a^2 - b^2) = (√a^2 + √b^2)(√a^2 - √b^2)

(x^2 - (-81) = (x + √-81)(x - √-81)

we can remove the - from under the radical by multiplying it by i.

(x^2 - (-81) = (x + i√81)(x - i√81)

(x^2 - (-81) = (x + 9i)(x - 9i)

we can check our answer by using foil:

x^2 - 9ix + 9ix - 81i^2

x^2 - 81^2

i^2 = -1

x^2 + 81