Answer:
35/9
Explanation:
What we need to know:
Parallel lines have the same slope
slope intercept form: y = mx + b
m = slope
The first thing we will want to do is put both equations in slope intercept form.
We must do this so we can identify the slope.
First equation:
3x + 7y + 1 = 0
Solve for y
Subtract 1 from both sides
3x + 7y + 1 - 1 = 0 - 1.
3x + 7y = -1
Subtract 3x from both sides
3x - 3x + 7y = -1 - 3x
7y = -3x - 1
Divide both sides by 7
7y/7 = (-3x - 1)/7
y = -3/7x - 1/7
So the equation of the first line is y = -3/7x - 1/7
Second equation:
5x + 3my – 2 = 0
Solve for y
Subtract 5x from both sides
5x - 5x + 3my - 2 = 0 - 5x
3my - 2 = -5x
Add 2 to both sides
3my - 2 + 2 = -5x + 2
3my = -5x + 2
Divide both sides by 3m
3my/3m = (-5x + 2)/3m
y = -5x/3m + 2/3m
So the equation of the second line is y = -5x/3m + 2/3m
So we have the two equations:
y = -3/7x - 1/7 and y = -5x/3m + 2/3m and we want to find the value of m if the two lines are parallel
Lines that are parallel have similar slopes
So the slope of the first equation should be the same as the slope of the second equation
The slope of y = -3/7x - 1/7 is -3/7 as it takes the spot of "m" in y = mx + b.
The slope of y = -5x/3m + 2/3m is -5/3m as it takes the spot of "m"
If the slopes of parallel lines must be similar than -3/7 = -5/3m
(Note that we've just created an equation that we can use to solve for m)
We now solve for m
-3/7 = -5/3m
Cross multiply
3*-3m = -9m
7*-5=-35
we acquire -35 = -9m
Divide both sides by -9
-35/-9 = 35/9
-9m/-9=
We're left with m = 35/9
So we can conclude that the value of m would be 35/9 if the two lines are parallel