Ques: Find the equation of the line that passes through the y-intercept of the line 3x+5y+2=0 and is parallel to the line 2x-4y-1=0.
From 3x+5y+2=0 , i found out that y-intercept= -2/5 x-intercept= -2/3
From 2x-4y-1=0 the, i found out that m= 1/2
Since m1=m2, i sub into the formula: y+2/5=1/2(x+2/3)
answer i got is y=1/2x-1/15 but is wrong.
can anybody help? Thanks.
Rewrite in slope-intercept form is what I would do first, personally, for this type of problem.
y=(-3/5)x-2/5
y=(1/2)x-1/4
Since it'll be parallel to equation 2, y=mx+b m=1/2.
Now, with x=0 in the first equation, the y-intercept, y=(-3/5)(0)-2/5=-2/5. So y=(1/2)x+b must equal -2/5 when x=0. -2/5=b.
y=(1/2)x-2/5, or 5x-10y-4=0.
You aren't supposed to be paying attention to x-intercepts in this question. The y-intercept is the point on the graph where the line intersects the vertical y-axis, which is at x=0, no? Therefore, to find where the graph passes through the y-axis, you must set x=0 and evaluate the equation, which will return the y-intercept.
(Just for reference, the x-intercept is solved by substituting 0 in place of y and solving for x, but that isn't necessary for this problem)