2004 AMC 12A Problem 5

Below is the professionally curated solution for Problem 5 of the 2004 AMC 12A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2004 AMC 12A solutions, or check the answer key.

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Concepts:slopecoordinate geometry

Difficulty rating: 1120

5.

The graph of a line y=mx+by = mx + b is shown. Which of the following is true?

mb<1mb \lt -1

1<mb<0-1 \lt mb \lt 0

mb=0mb = 0

0<mb<10 \lt mb \lt 1

mb>1mb \gt 1

Solution:

The yy-intercept of the line is between 00 and 1,1, so 0<b<1.0 \lt b \lt 1.

The slope is negative and shallow, between 1-1 and 0,0, so 1<m<0.-1 \lt m \lt 0.

The product mbmb is therefore negative with absolute value less than 1,1, giving 1<mb<0.-1 \lt mb \lt 0.

Thus, the correct answer is B.

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