Answer:
66
Step-by-step explanation:
Use the combination formula.
Answer:

Step-by-step explanation:
=
=
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Answer:
39 active volcanoes.
Step-by-step explanation:
Subtract 169 (whole) from 130 (part). 9 - 0 = 9, 6 - 3 = 3, and 1 - 1 = 0. Therefore, 169 - 130 = 39
The term in the expansion:
T ( k+1) = n C k * A^(n-k) * B^k.
In this case: n = 11, k + 1 = 8, so k = 7.
A = x, B = - 3 y
T 8 = 11 C 7 * x^(11-7) * ( - 3 y )^7 =
=( 11 *10 * 9 * 8 * 7 * 6 * 5 ) / ( 7 * 6 * 5 * 4 * 3 * 2 * 1 )* x^4 * ( - 2,187 y^7 ) =
= 330 * ( - 2,187 ) x^4 y^7 = - 721,710 x^4 y^7
Answer: The 8th term in expansion is
If we draw a perpendicular line from one of the vertices of the triangle we get 2 right angled triangles each with altitude 9 ins and vertex angle = 30 degrees. So:-
cos 30 = 9 /h where h = one of the sides of the equilateral triangle
h = 9 / cos 30 = 10.392 inches
Therefore the perimeter of the triangle = 3 * 10.392 = 31.1769 ins
Answer is 31.18 inches to the nearest hundredth.