Answer:
1) The equation of a line is
.
2) The equation of the line that passes through the points (2,4) and (3,7) is 
3) The equation of the line that has slope m = −2 and y-intercept equal to -1 is 
4) The slope-intercept form of
is
, where the slope is zero and the y-intercept is (0, 7).
Step-by-step explanation:
1) The equation of a line with slope <em>m</em>, passing through the point
, is

We know that
and the point is (1,8). Therefore, the equation of the line is

2) The equation of a line is typically written as

where m is the slope and b is the y-intercept.
The slope of a line is a measure of how fast the line "goes up" or "goes down" and is given by

To find the equation of the line that passes through the points (2, 4) and (3, 7), the first step is to find the slope.
Applying the definition of the slope, we get that

Now, we find the y-intercept with the help of point (2, 4) and the general form of the equation of a line

The equation of the line that passes through the points (2,4) and (3,7) is 
3) The equation of the line that has slope m = −2 and y-intercept equal to -1 is

4) The slope-intercept form of
is
, where the slope is zero and the y-intercept is (0, 7).