Question

Write the point-slope equation of the line that passes through(3,5) and (7,1)

Answer 1

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)