The girls fill the roles of a grandmother, mother, and daughter by permutation. It is a way, especially one of several possible variations, in which a set or number of things can be ordered or arranged. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
X= pi/4 +k(pi)
(This may not be correct sorry)
Number of strings =

= 21 x 21 x 21 x 21 x 21 x 5 = 20 420 505
Answer: 20 420 505
Answer:
a = 9
Step-by-step explanation:
First we need to add (x^2+3x) to (3x^2+ax),
(x^2+3x)+(3x^2+ax)
Expand
= x^2+3x+3x^2+ax
Collect the like terms
= x^2+3x^2+3x+ax
= 4x^2 + 3x + ax
= 4x^2+(3+a)x
Equate the solution to 4x^2+12x
4x^2+(3+a)x = 4x^2+12x
Comparing the like terms on both sides
(3+a)x =12x
3 + a = 12
a = 12 - 3
a = 9
Hence the value of a is 9
√105 is written in simplest form already.
The answer would be D. √105