Question

What is the equation of a line through the points (0, 9) and (3, 0)?

because m = StartFraction 9 minus 0 Over 0 minus 3 EndFraction; y = –3x + 9 because m = StartFraction 9 minus 0 Over 0 minus 3 EndFraction; y = –3x + 3 because m = StartFraction 3 minus 0 Over 0 minus 9 EndFraction; y = negative one-third x + 9
because m = StartFraction 3 minus 0 Over 0 minus 9 EndFraction; y = negative one-third x + 3 Mark

Answer 1

because m = StartFraction 9 minus 0 Over 0 minus 3 EndFraction; y = –3x + 9

Explanation:

Answer 2

m = StartFraction 9 minus 0 Over 0 minus 3 EndFraction; y = –3x + 9

Explanation:

The given points are the y-intercept and the x-intercept, so they can be used directly in the intercept form of the equation of a line.

x/(x-intercept) +y/(y-intercept) = 1

x/3 +y/9 = 1

Multiplying by 9 gives ...

3x +y = 9

This can be rearranged to the slope-intercept form ...

y = -3x +9

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The answer selection shown above is the only one that matches the slope and y-intercept of the line through the given points.