Answer:
6
Step-by-step explanation:
=4!/(4-2)!2!
=4x3x2x1/2x2
=12/2
=6
Answer: 620
Step-by-step explanation:
$40 x 5.5 hrs = $220 This means that she earned $220 tutoring the first student.
$40 x 10 hrs = $400 She earned $400 tutoring the second student.
$220 + $400 = $620 She earned $620 in total that week.
Let the three gp be a, ar and ar^2
a + ar + ar^2 = 21 => a(1 + r + r^2) = 21 . . . (1)
a^2 + a^2r^2 + a^2r^4 = 189 => a^2(1 + r^2 + r^4) = 189 . . . (2)
squaring (1) gives
a^2(1 + r + r^2)^2 = 441 . . . (3)
(3) ÷ (2) => (1 + r + r^2)^2 / (1 + r^2 + r^4) = 441/189 = 7/3
3(1 + r + r^2)^2 = 7(1 + r^2 + r^4)
3(r^4 + 2r^3 + 3r^2 + 2r + 1) = 7(1 + r^2 + r^4)
3r^4 + 6r^3 + 9r^2 + 6r + 3 = 7 + 7r^2 + 7r^4
4r^4 - 6r^3 - 2r^2 - 6r + 4 = 0
r = 1/2 or r = 2
From (1), a = 21/(1 + r + r^2)
When r = 2:
a = 21/(1 + 2 + 4) = 21/7 = 3
Therefore, the numbers are 3, 6 and 12.
Add 5 to both sides to get x alone and you will have your answer which is x= -3
The number of members in 20 families in a village is given as 6,8,6,3,2,5,7,8,6,5,5,7,7,8,6,6,7,7,6,5
svetoff [14.1K]
Answer:
2
6,6,6,6,6,6=more than 5
7,7,7,7,7=has exactly 5 members
