Question

The equation yˆ=20646 (0.86)x

estimates the value of a brand of car x years after it was purchased new. Milo purchased this brand of car when it was new.

To the nearest dollar, what will be the approximate value of Milo's car 11 years after he purchased it?


$20,637


$17,756


$5138


$3929
The equation yˆ=−5.131x2+31.821x−3.333

approximates the number of people standing in line to catch a commuter train x hours after 5 a.m.

What is the best estimate for the number of people in line at 7 a.m.?


23


40


27


32

Answer 1

For the equation:
y = 20,646 · 0.86^x
When: x = 11
y = 20,646 · 0.86^11 = 20,646 · 0.19 = 3,929.33 ≈ 3,929
Answer: D ) $3,929
For y = - 5.131 · x² + 31.821 x - 3.3333
7 am - 5 am = 2 , so: x = 2
y ( 2 ) = - 5.131 · 2² + 31.821 · 2 - 3.3333 =
= - 5.131 · 4 + 63.642 - 3.3333 = -20.524 + 63.642 - 3.3333 = 39.78 ≈ 40
Answer: B ) 40.