Choose the equation of the line passing through the point (6, -2) and parallel to y = x + 7.

y = x + 8

y = x - 4

y = x + 4

y = x - 8

Question

Choose the equation of the line passing through the point (6, -2) and parallel to y = x + 7.

y = x + 8

y = x - 4

y = x + 4

y = x - 8

jim_thompson5910 · Answer

each answer choice has the same slope (which is 1), so we don't have to worry about the slope

jim_thompson5910 · Answer

all we need to do is plug in the point (6,-2) into each answer choice and see if we get a true equation or not

jim_thompson5910 · Answer

for instance, in choice A

y = x + 8

-2 = 6 + 8 ... plug in (6,-2)

-2 = 14

that's false, so (6,-2) is NOT on the line y = x + 8

so choice A is out

jim_thompson5910 · Answer

see how to do this?

anonymous · Answer

Yes thank you I think I can do it now.

jim_thompson5910 · Answer

alright great, yw

whpalmer4 · Answer

You could also construct the equation:  we know the slope is 1, and a line with slope 1 going through that point would be$$y- (-2) = (1)(x-6)$$$$y+2=x-6$$$$y+2-2=x-6+2$$\(you can finish the simplification)

whpalmer4 · Answer

(I used the point-slope formula for a line of slope $m$ going through point $(x_0,y_0)$:$$y-y_0 = m(x-x_0)$$

whpalmer4 · Answer

when I was learning this stuff, we never had multiple-choice questions, we always had to figure the darn thing out ourselves :-)

anonymous · Answer

Thanks whpalmer4 I think I understood it more now. Thank You!!

jim_thompson5910 · Answer

whpalmer4's way is probably better since you won't have multiple choice to rely on all the time

but if you do have multiple choice answers, you can use this quick method to check

anonymous · Answer

Okay jim_thompson5910 thanks!

whpalmer4 · Answer

Yep.  I'm not generally in favor of multiple-choice exams, but if they're going to give them to you, you might as well take advantage of the opportunities to solve or check your work in any way available!

anonymous · Answer

Ya so I think the answer is the last one right?

jim_thompson5910 · Answer

correct

whpalmer4 · Answer

uh, let's see:

point is (6,-2) right?

y = x-8

-2 = 6-8
-2 = -2
looks good.

whpalmer4 · Answer

your medal is in the mail :-)

anonymous · Answer

Thank you guys! You really helped me a lot since I had to do this for an exam. 
And thank you whpalmer4 for the medal!!

anonymous · Answer

y = x - 4

whpalmer4 · Answer

@dpasingh you think y=x-4 goes through the point (6,-2)?  Let's check!

y = x-4
(-2) = (6)-4
-2 = 2

Are you sure about that?