Algebra
posted by John on .
Two more Algebra questions : Having some difficulty with these.
Drawing a blank on this one, not sure where to start.
Find the equation, in standard form, with all integer coefficients, of the line perpendicular to x + 3y = 12 and passing through (9, 5).
I have half a solution to this one:
Solve the system of equations using the substitution method.
If the answer is a unique solution, present it as an ordered pair: (x, y). If not, specify whether the answer is “no solution” or “infinitely many solutions.”
4x + y = 4
2x + 8y = 0
First I did
4x  4x + y = 4  4x
y = 4  4x
then
2x + 8(44x) = 0
2x + 32  32x = 0
2x + 32  32x = 032
2x  32x = 32
30x = 32
30x/30 = 32/30
x = 32/30
x = 16/15
then
y = 4  4x
y = 4  4(16/15)
This is where I am stuck...
So i got x = 16/15 an y = ?

(I did not check you "x" if it is correct or not)
First, you need to simplify 4{16/15)
Then, find a common denominator
New Equation:
y = 60/15  64/15
Answer:
y = 4/15