Answer:
y=
x+
Explanation:
-3x-4y=12
1. First we need to get the equation in the form of y=mx+c to do this we add 3x to both sides and then divide it by -4 on each side to get
(add 3x to both sides) = -4y=3x+12
(divide each side by -4)= y= -
x -3
2. to find the perpendicular gradient we find the reciprocal of the original gradient
the reciprocal of -
is
3. we can check this by multiplying them and seeing of we get -1
-
x
= = -1
4. we then sub in the gradient
in y=mx+c this gives us
y=
x +c
5. to find the value of c we substitute the coordinates into the equation to get ( we do this by expanding the brackets and getting c on it own)
-3=
(-4) +c
-3= -
+c
=c
6. we sub
=c back into y=
x +c this gives us
y=
x +
7. Therefore our final answer is
y=
x +