Choose the equation that represents a straight line that is positive in the domain 8 > x
and passes through the point (0,9).
To solve this problem, we'll identify the correct equation of a line that passes through the point (0,9) and remains positive when x<8.
- Step 1: Identify the y-intercept using the given point (0,9). The y-intercept c is 9, leading to a partial equation: y=mx+9.
- Step 2: Determine the appropriate slope m so that the line is positive for x<8. This means the line should decrease (positive to the right implies negative to the left) as x decreases from 8, requiring a negative slope.
- Step 3: Given the provided choices, y=−181x+9 matches these requirements because it incorporates:
- The correct y-intercept at 9.
- The negative slope, ensuring y is positive for x<8.
The correct line equation that fulfills these conditions is therefore y=−181x+9.
y=−181x+9