Question

what is the equation of the line that passes through (-9,12) and is perpendicular to the line whose equation is y=1/3*x+6?
y=-1/3*x+15
y=-3*x-15
y=-1/3*x-13
y=-3*x+27

Answer 1

first, can you tell me what the slope of y = 1/3x + 6 is ??

Answer 2

no idk

Answer 3

lord jesus

Answer 4

please bless this beautiful girl in hopes that she gets the right answer...amen

Answer 5

if not, I can show you how to find the slope....in y = mx + b, the slope can be found in the m position....so what is the slope of the original equation ?

Answer 6

y = mx + b
y = (1/3)x + b

do you see that the slope is 1/3 ?

Answer 7

we needed to find the slope because a negative reciprocal slope is needed for a perpendicular line. To find the negative reciprocal of 1/3, we just flip the slope and change the sign....so the new slope for out perpendicular line is -3/1....see how I flipped the slope and changed the sign ....any questions so far ?

Answer 8

so its a or c

Answer 9

now we will use y = mx + b
slope (m) = -3/1
(-9,12)...x = -9 and y = 12
now we sub and since we already know slope(m) and we have our points x and y, we just need to find b, the y intercept.
so we sub
y = mx + b
12 = -3/1(-9) + b
12 = 27 + b
12 - 27 = b
- 15 = b

so the perpendicular equation is : y = -3x - 15

Answer 10

any questions at all ??

Answer 11

well....if you have any, just ask