Geometry: CC 2015 > Chapter 9: Chapter 9 Test > Chapter Test 9
1 answer:
You might be interested in
Answer: y - 1 = –(x –7)
or y –5 = –1(x –3)
The attachment shows the graph of these equations (identical)
Step-by-step explanation:
The basic form for a point-slope equation is
y - b = m(x - a)
a is the x-value from the given coordinate, b is the y-value form the given coordinate, m is the slope. x and y are the variables in the function.
To find the slope, m, use the given coordinates. Get the difference in the y-values and divide by the difference in the x-values. This is "rise over run."
Subtract the first coordinate from the second coordinate.
Given coordinate points: (3,5) and (7,1) substitute values:
m= 1 –5 / 7 –3 becomes m= –4/4 so the slope, m = –4/4
That is –1 The "1" is "understood," so only the negative sign represents the slope in the equation
To write the equation: Take the basic form, substitute b and a values from either given coordinate. And use the value of m we just calculated.
y - b = m(x - a) Using the second coordinate: (7,1)
y - 1 = –(x –7)
or using the first coordinate:
y –5 = –(x –3)
