Answer:
y = (1/7)x - 3
can be rewritten as
7y = x - 21
Explanation:
Equation of a line in slope intercept form is
where
m = slope of the line and c is the y intercept ie the y value when x = 0
m and c are constants
Slope is also referred to rise/run . This represents the ratio of the difference in y values to the corresponding difference in x values for any two points on the graph
Looking at the graph we can see that the line crosses the y axis at y = -3 so in the equation, c = -3
To find the slope first take any two points on the line. Let's choose the points (0,-3) and (7,-2) since these are integer coordinate values
Find the difference in y values -2 - (-3) = -2 + 3 = 1
Find the difference in corresponding x values: 7-0 = 7
Slope = (difference between y values)/(difference between x values) = 1/7
Therefore equation of the line in slope-intercept form is
y = (1/7)x - 3
which can also be written as
7y = x - 21 by multiplying both sides by 7
Either form should be acceptable
Answer:
y = (1/7)x - 3
or
7y = x-21
We can double check our answer by choosing another point through which the line passes and see if the above equation fits
We can see that the line passes through (-7, -4). ie at x = -7, y should be -4
Plug in -7 into the first form of the equation
y = -7/7 - 3 = -1-3 = -4
Plugging into the second form
7y = -7 - 21 = -28
y = -28/7 = -4
Hence verified
Attached graph shows that the line does pass through all three points we have chosen