I hope you know what '!' means
2!=2
3!=6
4!=24
basicalkly times every natural number including and before that number
nCr=
so
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Answer:
n = 60.22
Step-by-step explanation:
Hello
To find Sn, we need to draw out equations for each a₇ and a₁₉
In an arithmetic progression,
Sn = a + (n-1)d
Where Sn = sum of the A.P
a = first term
d = common difference
a₇ = 32
32 = a + (7-1)d
32 = a + 6d ........equation (i)
a₁₉ = 140
140 = a + (19-1)d
140 = a + 18d .........equation (ii)
Solve equation (i) and (ii) simultaneously
From equation (i)
32 = a + 6d
Make a the subject of formula
a = 32 - 6d .....equation (iii)
Put equation (iii) into equation (ii)
140 = (32 - 6d) + 18d
140 = 32 - 6d + 18d
Collect like terms
140 - 32 = 12d
12d = 108
d = 108 / 12
d = 9
Put d = 9 in equation (i)
32 = a + 6(9)
32 = a + 54
a = 32 - 54
a = -22
When Sn = 511
Sn = a + (n - 1)d
Substitute and solve for n
511 = -22 + (n-1) × 9
511 = -22 + 9n - 9
511 = -31 + 9n
511 + 31 = 9n
542 = 9n
n = 542 / 9
n = 60.22
Answer:
B
Step-by-step explanation:
An equation of a circle:
(x - a)² + (y - b)² = r²
(a; b) - a coordinates of a center
r - a radius
r = 5; P(6; 1) ⇒ a = 6 and b = 1
therefore
(x - 6)² + (y - 1)² = 5²
check:
A) Q(1; 11)
L = (1 - 6)² + (11 - 1)² = (-5)² + 10² = 25 + 100 = 125
R = 25
L ≠ R
B) R(2; 4)
L = (2 - 6)² + (4 - 1)² = (-4)² + 3² = 16 + 9 = 25
R = 25
L = R - CORRECT
C) S(4; -4)
L = (4 - 6)² + (-4 - 1)² = (-2)² + (-5)² = 4 + 25 = 29
R = 25
L ≠ R
D) T(9; -2)
L = (9 - 6)² + (-2 - 1)² = 3² + (-3)² = 9 + 9 = 18
R = 25
L ≠ R
Answer: B) R(2; 4).
Answer:
y = 
Step-by-step explanation:
Given
ya + yv = t ← factor out y from each term on the left side
y(a + v) = t ( divide both sides by a + v )
y =
If the line segment is perpendicular to a line with the slope of -4, that means the line segment has a slope of 1/4.
First let's make an equation for the line segment using the slope of 1/4 and the point at (2,6) to find the final piece, the y-intercept
y = mx + b
6 = 1/4(2) + b
6 = 2/4 + b
24/4 = 2/4 + b
22/4 = b
y = 1/4 x + 22/4
6 = 1/4(2) + 22/4
6 = 2/4 + 22/4
6 = 24/4
6 = 6 <-- proves that this equation is correct
Now you may plug in the x to find y. ( 8 , y )
y = 1/4(8) + 22/4
y = 8/4 + 22/4
y = 30/4 = 15/2 = 7.5
