Can someone help me with Slope and Y-intercept?

Question

I don't want the answer just how to do it. I don't get it.

The question is this:
Determine the equation of the line that passes through J(5,5) and is:

a) parallel to the line 3x + 4y = -16
b) perpendicular to the line 5x + 2y = 10

How am I supposed to this?

Answer 1

No problem. Put the equation(s) (A and B) in slope-intercept form (y=mx+b) The m is the slope of the line so, for the line you want parallel, it will also be that lines slope. For the one you want perpindicular, the slope will be -1/m.

To find the y-intercept of the two equations you have, just substitute the x and y coordinates of the point that it has to pass thru (5,5) for the x and y in the equation, then solve it for the constant term (the b) and you're done.

HTH

Doug

Answer 2

Well, the two options a and b provide you with enough information to figure out the slope of your equations. First step to solve these problems is to isolate your y's so that you have an equation in the form y=mx + b where m is the slope and b is the y-intercept. So for a, y= (- 16 - 3x) / 4 or simplified, y= - 4 - 3/4(x) and you can rearrange this so the equation reads y= - 3/4(x) - 4. Since the equation of the line that passes through J(5,5) is parallel to the line y= -3/4(x) - 4, it has the same slope. So your skeleton equation would read y= -3/4x + b. Now we have to solve for b and this is done by plugging in the point given, (5,5) into your skeleton equation. So, 5 = -3/4 (5) +b or simplified, 5= -15/4 +b. Add 15/4 to both sides.. 5 = -15/4 + b, 5 can be re-written as 20/4, so it would be 35/4 = b. So for part a, the equation should be y= -3/4x + 35/4.

For part b, the line is perpendicular to the line 5x +2y=10 or y= (10 - 5x ) 2 or y=5 - 5/2(x) or y= - 5/2x) + 5. Since the line passing through (5,5) is perpendicular to the equation in part b, the slope for the unknown line is the reciprocal of the line in part b. It is also the opposite sign of the slope given in part b. So the skeleton equation would read, y= 2/5 x + b. To solve for b, plug in your point (5,5) and you get 5=2/5 (5) + b or 5=2 +b. Subtract 2 from both sides to isolate your b and you get 3 = b. So the equation for part b should read y = 2/5 x +3. Hope these are right :D Good luck and I hope you understood my steps.

Answer 3

The equation for slope is rise over run. rise = y, run = x. to get the equation u need to groups of plots. e.g.(3,5) and (4,2). u need to subtract y1 from y2(2-5=-3) and then subtract x1 from x2(4-3=1) ur answer for the slope is 3 over 1.

The y intercept is where the line from point a to point b cross the y axis. From there you find the slope.

e.g. your equation could be somethin like y=3x+5

you need to take the sign w/ u so the numer alone(+5) is where ur y intercept is. u then need to put 3 over a one and that is ur slope. From the +5 you need to go up 3 and right 1, Up 3 right 1. After that you draw a straight line connecting the points and then you have ur slope and ur y intercept.

Answer 4

You need to find the slope of the line 3x+4y = -16; that will have the same slope as your answer. The slope of 5x+2y = 10 will be the negative reciprocal of your answer's slope.

Answer 5

you need to graph it... if you know points you can graph and determine the slope