Question

Please Check My Answer!

The graph of y = 2/3x - 12 intersects the y-axis at Q(0,-12) and is perpendicular to a line joining Q to the point P(x, 0).  Find x.

My answer: x = -8

Answer 1

@Nnesha

Answer 2

Am i correct or not?

Answer 3

any work??? :=))

Answer 4

Yes.

Answer 5

try finding out the slope of line joining (-8,0) and (0,-12) then check if its appropriate or not :) u'll find out if ur correct or not

Answer 6

Perpendicular Slopes = opposite reciprocal
\[\large y = mx + b \]

y = y-coordinate
m = slope
x = x-coordinate
b = y-intercept

Our equation:
\[\large y = \frac{ 2 }{ 3 }x - 12\]
Slope: \(\large \frac{2}{3}\)
Perpendicular Slope is \(\large -\frac{3}{2}\)

New equation with perpendicular slope:
\[\large y = -\frac{ 3 }{ 2 }x - 12\]
We have the coordinate: \(\large (x, 0)\) where \(0\) is the y-coordinate and \(x\) is the unknown x-coordinate.

\(\large 0 = -\frac{3}{2} x- 12\)
Solve for x to get: \(\large -8\)

Answer 7

that's correct. to double check you can find slope of two points as mentioned by imqwerty

Answer 8

okay thanks :)

i have another question can you please check my answer:
A line with x-intercept -4 passes through (2,6) and (p,10).  Find p.

answer: p = 6

Answer 9

check your answer
let p=6
(2,6)(6,10) find slope and y-intercept and then substitute y for zero to find x-intercept if you get -4 as final answer then yes that is correct value for p