Select the equation of the line parallel to the equation 2x + 4y = -5 that passes through the point (-4, -8). a). x + 2y = 16 b). 2x + y = -16 c). 2x + 4y = -9 d). x + 2y = -20
Mathematics · Middle School · Thu Feb 04 2021
Answered on
Given:
Points (-4, -8 )
x1 = -4
y1 = -8
Parallel to 2x + 4y = -5
Solve for y.
4y = -2x - 5
y = -½x - 5/4
Parallel, means they have same slope
m = -½
Formula for the point-slope form:
y -y1 = m (x - x1)
Formula for the slope-intercept form
y = mx + b
Solution:
Solve for point-slope form first, before going to slope-intercept form.
Substitute the given values of x1, m and y1 to the formula for the point-slope form.
y - (-8) = -½ ( x - (-4) )
y + 8 = -½ (x + 4)
In order to equate to slope-intercept form, we simply need to distribute -½ to each value inside the parenthesis, and then transpose 8 to the other side of the equation, hence it must be taken to note that in transposing a number, the sign changes.
y + 8 = -½x - 2
y = -½x - 2 - 8
y = -½x - 10
Final answer:
y = -½x - 10