Hi, been having problems with these questions.. I got to be honest.. I need this to help me get through my college course, but it's a high school question.. just find it really hard.. thanks in advance:

Question:
1.)

Find the equation of a straight line that passes through the point (3, -1) and is parrallel to the line y = 2x + 1. Give your answer in the form y = mx + c

2.)

Find the equation of a straight line that passes through the point (3, -1) and is perpendicular to the line y = 5x - 2. Give your answer in the form ax + by + c = 0

Thanks, if I find anymore difficult.. I will shout back.

Thanks,

Timmy, 15

2. Originally Posted by Biggzi
Hi, been having problems with these questions.. I got to be honest.. I need this to help me get through my college course, but it's a high school question.. just find it really hard.. thanks in advance:

Question:
1.)

Find the equation of a straight line that passes through the point (3, -1) and is parrallel to the line y = 2x + 1. Give your answer in the form y = mx + c
If the two lines are parallel, they have the same slope. Remember that in the equation of a line $\displaystyle (y = mx+c)$ , $\displaystyle m$ is the slope.

We have also been given a point on the line $\displaystyle (3,-1)$ , so we need to simply plug those values into our equation to solve for $\displaystyle c$.

$\displaystyle -1 = 2(3) + c$

$\displaystyle c = -7$

$\displaystyle y = 2x - 7$

2.)

Find the equation of a straight line that passes through the point (3, -1) and is perpendicular to the line y = 5x - 2. Give your answer in the form ax + by + c = 0

Thanks, if I find anymore difficult.. I will shout back.

Thanks,

Timmy, 15
If the lines are perpendicular, the slope is the negative reciprocal. Therefore, we can say that the slope of the line is $\displaystyle -\frac{1}{5}$ . Once again we have been given a point on the line, so the rest should be straight forward.

3. Thanks ever so much my friend.

For the second equation is $\displaystyle x +5y +8 = 0$ right?

4. Originally Posted by Biggzi
[snip]
2.) Find the equation of a straight line that passes through the point (3, -1) and is perpendicular to the line y = 5x - 2. Give your answer in the form ax + by + c = 0
[snip]
Originally Posted by Biggzi
Thanks ever so much my friend.

For the second equation is $\displaystyle x +5y +8 = 0$ right?
Does the given point (3, -1) satisfy this equation ....?