Ayanna is 17 and Brittany is 14.
To find this, let's write two equations using the given information.
a = b + 3
3b + 2a = 76
Now, just substitute the first equation into the second and solve.
3b + 2(b + 3) = 76
3b + 2b + 6 = 76
5b = 70
b = 14
If Brittany is 14, then Ayanna is 3 years older at 17.
= 1/2 (a + b) h let me know if this helps :)
Answer: [A]: "library card".
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Explanation: One would need a valid, government-issued photo ID card (i.e. that has not expires).
Although SOME library cards include one's picture, library cards do not constitute "valid ID's" because they are not "government-issued" and would, theoretically, be easy to be made fraudulently (e.g. not have security-issued seals and features).
Even "school ID's"; or "college ID cards"; even if "current" (e.g. currently enrolled" with a photo ID) would not be considered "official" and would only be considered "secondary ID".
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The disk method will only involve a single integral. I've attached a sketch of the bounded region (in red) and one such disk made by revolving it around the y-axis.
Such a disk has radius x = 1/y and height/thickness ∆y, so that the volume of one such disk is
π (radius) (height) = π (1/y)² ∆y = π/y² ∆y
and the volume of a stack of n such disks is
where 
is a point sampled from the interval [1, 5].
As we refine the solid by adding increasingly more, increasingly thinner disks, so that ∆y converges to 0, the sum converges to a definite integral that gives the exact volume V,
