Problema Solution
Find equations (in slope-intercept form) for the line;
a. parallel to the line 24x − 3y = 7 and passing through (−1, 4).
b. perpendicular to the line y = −(4/5)X-7 passing through (1, 6).
Answer provided by our tutors
A "slope-intercept" form of a line is:
y = mx + b
where "m" is the slope and "b" gives the y-intercept.
a.parallel to the line 24x − 3y = 7 and passing through (−1, 4)
since the slopes of parallel lines are equal we will write 24x − 3y = 7 in slope intercept form
24x − 3y = 7
3y = 24x - 7 divide both sides by 3
y = 8x - 7
thus m = 8
now the only thing left to find is b
y = 8x + b goes trough (−1, 4) that is
4 = 8(-1) + b
b = 12
finally we have the slope-intercept equation of the wanted line:
y = 8x + 12
b.perpendicular to the line y = −(4/5)x − 7 and passing through (1, 6)
for perpendicular line the perpendicular slopes are negative reciprocals of each other
the slope of the line y = −(4/5)x − 7 is -4/5
negative reciprocal fo -4/5 is -(-4/5)^(-1) = 5/4 thus m = 5/4
now the only thing left to find is b
y = (5/4)x + b goes trough (1, 6) that is
6 = (5/4)*1 + b
b = 6 - 5/4
b = 19/4
finally we have the slope-intercept equation of the wanted line:
y = (5/4)x + 19/4