Answer:
si
Step-by-step explanation:
espero ayudarte XD
Answer:
a20 = -99
Step-by-step explanation:
hello :
the nth term in this arithmetic sequence is : an = a1 + (n -1 )d
a1 = 15 a2 = 9 d = a2-a1 = 9-15 = -6 ( common difrence)
an = 15 + (n -1 )(-6)
an = 15+6-6n
an = -6n+21
the 20th term when n = 20 : a20 = -6(20)+21 = -99
Mode is the answer that shows up the most, for example if your numbers were 10, 10, 14, 17, 19, the mode would be 10.
You find the median by putting the numbers in order from least to greatest, and finding the number in the middle of those, for example 10, 10, 14, 17, 19, the median would be 14.
The mean is subtracting the smallest number from the largest number, using my example that would be 19-10, so the mean is 9, if that makes any sense.
Answer:
see explanation
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k ) are the coordinates of the centre and r is the radius
Given
16 + x² + y² - 8x - 6y = 0 ( subtract 16 from both sides )
x² + y² - 8x - 6y = - 16 ( collect x and y terms together )
x² - 8x + y² - 6y = - 16
Use the method of completing the square
add ( half the coefficient of the x/y terms)² to both sides
x² + 2(- 4)x + 16 + y² + 2(- 3)y + 9 = - 16 + 16 + 9
(x - 4)² + (y - 3)² = 9 ← in standard form
with centre (4, 3 ) and r = 
= 3
This is a circle with centre (4, 3 ) and radius 3
It is about probability, so you multiply in descending order
5x4x3x2x1 = 120
