Question

Write an equation of the line that is parallel to 2x + 4y = 6 and passes through the point (6, 4). A) y = 2x + 4 B) y = 2x - 8 C) y = -2x + 16 D) y = - 1 2 x + 7

Answer 1

Answer:

$\large\boxed{D.\ y=-\dfrac{1}{2}x+7}$

Step-by-step explanation:

$\text{Let}\\k:\ A_1x+B_1=C_1\\\\l:\ A_2x+B_2y=C_2\\\\\text{then}\\\\k\ \parallel\ l\iff A_1=A_2\ \wedge\ B_1=B_2\\==========================$

$\text{We have the equation:}\ 2x+4y=6\\\\\text{Therefore the equation of a parallel line is:}\ 2x+4y=C\\\\\text{Put the coordinates of the given point to the equation and solve for}\ C:\\\\(6,\ 4)\to x=6,\ y=4\\\\C=2(6)+4(4)\\C=12+16\\C=28\\\\\text{The equation in the standard form:}\\\\2x+4y=28$

$\text{Convert to the slope-intercept form}\ y=mx+b:\\\\2x+4y=28\qquad\text{subtract}\ 2x\ \text{from both sides}\\\\4y=-2x+28\qquad\text{divide both sides by 4}\\\\y=-\dfrac{2}{4}x+\dfrac{28}{4}\\\\y=-\dfrac{1}{2}x+7$