Question

Write the equation of the line parallel to 4y - x = -20 that passes through the point (8,3).

Answer 1

y= ¼x +1

Explanation:

Rewriting the equation into the slope-intercept form (y= mx +c, where m is the gradient and c is the y- intercept):

4y -x= -20

4y= x -20 (+x on both sides)

y= ¼x -5 (÷4 throughout)

Thus, slope of given line is ¼.

Parallel lines have the same gradient.

Gradient of line= ¼

y= ¼x +c

To find the value of c, substitute a pair of coordinates into the equation.

When x= 8, y= 3,

3= ¼(8) +c

3= 2 +c

c= 3 -2

c= 1

Hence the equation of the line is y= ¼x +1.