What is the equation of a line that is: parallel to y=7x+9 and passes through (-2,-18). How would I do this?

1 Answer
Apr 15, 2018

Given: #y = 7x+9#

You change the #9# to an unknown constant #b#:

#y = 7x+b" [1]"#

Force the new equation to pass through the point #(-2,-18)# by substituting #x = -2# and #y = -18# into equation [1]:

#-18 = 7(-2)+b#

Solve for the value of b:

#-18 = -14+b#

#b = -4#

Substitute #b = -4# into equation [1]:

#y = 7x-4 larr# this equation must pass through the point #(-2,-18)#