Question

WILL FAN AND MEDAL
Line l is represented by the equation 2x+y=9

What it the Slope of a line parallel to line l?
What is the slope of the line perpendicular to line l?

Answer 1

first find the slope of \[2x+y=9\] by solving for \(y\) (in one step)

Answer 2

the slope of the parallel line will be the same
the slope of the perpendicular line will be the "negative reciprocal" i.e. flip it and change the sign

Answer 3

did you get that or no?

Answer 4

not really, sorry

Answer 5

you have \[2x+y=9\] and you want the slope
the slope of \[y=\color{red}mx+b\] is \(\color{red}m\) so you want to write the equation to look like that so you can see the slope with your eyeballs
that is why i said "solve for x"

Answer 6

i mean "solve for y"

Answer 7

\[2x+y=9\] subtract \(2x\) from both sides, what do you get?

Answer 8

you get y = 9 -2x

Answer 9

right, or \[y=\color{red}{-2}x+9\] making the slope ???

Answer 10

negative ?

Answer 11

lol yes it is negative for sure
more specifically it is \(-2\)

Answer 12

got that? it is the number in front of the x

Answer 13

yeah I got that

Answer 14

ok then the parallel line has the same slope

Answer 15

and the perpendicular is -1/2x?

Answer 16

no

Answer 17

the slope of the perpendicular line is what you are asked for, a number, no variable
it is the "negative reciprocal" you flipped it, but did not change the sign

Answer 18

i.e. the slope with be the number \(\frac{1}{2}\) the minus sign goes

Answer 19

1/-2?

Answer 20

\[-\frac{1}{2}=\frac{-1}{2}=\frac{1}{-2}\] but the negative reciprocal of \(-2\) is just \[\frac{1}{2}\] with no minus sign

Answer 21

thank you. Mind I tag you in 1 more?

Answer 22

no not at all

Answer 23

or you can post it here if you like