### Answer key for analytic geometry pre-test

**Part I - MC:**

1) a 2) c 3) d 4) d 5) c 6) b 7) c 8) a

**PART II - SA:**

1) using distance formula...

**r = 5.8**

2) using substitution, elimination or graphing and finding the pt of intersection on your calculator

**sol'n: (-4, -11)**

3)

**1 solution**(as seen by graphing circle and straight line)

4) using distance (from pt to line) formula...

**d = 5 (root 13) / 13**...(sorry about the lack of mathematical symbols, I never had a chance to download the software that produces them.

**PART III - LA**

1) Graph all lines on paper and find all 4 vertices (2 are y-intercepts, the other two are points

of intersection.

You must then find the equation of each diagonal line (using pt-slope formula from S2)...

The equations of the diagonals are: y = x - 2 and y = -(5/6)x + 4.

The point of intersection of these two diagonals is

**(3.3, 1.3).**

2) You substitute all three points, (10, 1500), (20, 2000) and (30, 1500) into the equation and

you end up with the following 3 x 3 system:

1) 100a + 10b + c = 1500

2) 400a + 20b + c = 2000

3) 900a + 30b + c = 1500

2) - 1): 300a + 10b = 500 4)

2) - 3): -500a - 10b = 500 5)

4) + 5): -200a = 1000

...therefore a = -5

....after more substitution... b = 200, c = 0

...therefore sol'n =

**(-5, 200, 0)**

.... h(t) = -5t^2 +200t

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