Question

What is the slope of a line perpendicular to the line with equation Y=5x-2

Answer 1

A. –2

B. 5

C. –5

D. - 1/5

Answer 2

For two lines to be perpendicular, we know that the slope of line 1 must be equal to the negative reciprocal of the slope of line two. i.e.:
\[(L1 \perp L2) \rightarrow (m1 = -\frac{ 1 }{ m2 }) \rightarrow (m2 = -\frac{1}{m1})\]

So, to find the slop of the second line, we first need to know the slop of the first line (m1)

Lucky for us our equation is already in the form:
\[y=mx+b\]

We know that in this form the slope is equal to 'm'. In this case m1 = 5.

Plug this into our equation from above:
\[m2=-\frac{1}{m1}\]
\[m2=-\frac{1}{5}\]

The slope of a line, perpendicular to \[y=5x-2\] is \[-\frac{1 }{ 5}\]

Some Notes:

-notice that the '-2' in the original equation doesn't come into play at all. Perpendicular doesn't depend on 'b'. It could have been anything and we would have gotten the same answer.

-If we wanted parallel instead of perpendicular it would have been even easier: m1=m2.

Answer 3

Thank you...that helps alot! (:

Answer 4

Got time for a few more?

Answer 5

Ya for sure.

Answer 6

Sorry bout that my computer is acting up..just give me a sec here(:

Answer 7

What is the Slpoe of a line paralell to the line with equation 5x-2y=11?
A 5/2
B-5/2
C-11/2
D-2/5

Answer 8

First to make this easier lets put the equation in the form \[y=mx+b\] We do this by solving for y.
\[5x-2y=11\]\[2y=5x-11\]\[y=\frac{5}{2}x-\frac{11}{2}\]

Good so far?

Answer 9

Yeah..im following so far(:

Answer 10

Ok. So with the equation in this form we can see that our slope, m1 is equal to \[\frac{5}{2}\]

In order for two lines to be parallel, the must have exactly the same slope. i.e.:
\[m_{1}=m_{2}\]

We just found out \[m_{1}=\frac{5}{2}\] so the answer is just \[m_{2}=m_{1}=\frac{5}{2}\]

The answer is A.

Answer 11

Ok... Yeah that does make sence:P Isnt Slope like have something to do with rise over run or is that something else?

Answer 12

The slope of any strait line is rise over run. As a formula:
\[m=\frac{ rise }{ run }=\frac{ \Delta y }{ \Delta x}=\frac{ y _{2}-y_{1} }{ x_{2}-x_{1} }\]

Answer 13

alright i think i can remember that...maybe.
Which of the following has a slope of -2 and a Y- intercept of 4?
A.Y=2x-4
B.Y=-2x-4
C. Y=2x+4
D.Y=-2x+4

Answer 14

So all the equations are already in the form
\[y=mx+b\]
In this formula we know that
\[m=slope\]and
\[b=Yintercept\]
So we can just plug in the values they give us:
\[y=mx+b\]\[y=−2x+4\]

The answer is 'D'.

Answer 15

Ok i think i understand all that..one more?

Answer 16

Sure

Answer 17

Which ordered pair is on teh praph of the equation 2x+5y=42
A(0,1)
B. (7,-2)
C. (3,-2)
D. (0,-1)

Answer 18

*the graph* sorry

Answer 19

The easiest way is to just just check them all one at a time. Let go:

A.
\[2x+5y=42\]\[2(0)+5(1)=42\]\[2+5=42\]\[7=42\] Nope.

Answer 20

Ok hold on.....none of them are going to work. Are you sure the question is right?

Answer 21

let me check again...

Answer 22

Yeah that is what the question was no wonder i got it wrong...sorry for the inconvenience. but thanks for the help with the other problems.

Answer 23

No problem.

Answer 24

Thanks Bye(: