Write the equation of the line that passes through the point (-2,4) and has a slope of 4. A) y = 4x - 4 B) y = 4x - 14 C) y = 4x + 12 D) y = 4x + 18
Mathematics · High School · Sun Jan 24 2021
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Given the point:
(- 2 ,4)
x1 = -2
y1 =2
Wirte the equation of the line, in slope -intercept form represented as,
y = mx + b
Before changing to slope-intercept form, you must first equate the line in point-slope form.
y -y1 = m (x - x1)
Solution:
Notice that we are missing the value of m, thus we can solve for m by using the slope formula.
m = x/y
m = -2/2
m = -1
Equate the given values in point-slope form.
(y - 2) = -1 (x - - (2))
y - 2= - 1 ( x + 2)
Change point-slope form in slope intercept form by distributing first the value of -1 to the parenthesis, and then transpose -2 on the other side of the equation, hence we must take note that in transposing a number, the sign changes.
y - 2 = -x - 2
y = -x - 2 + 2
y = -x
Final answer:
y = -x