How do you work our 3x=4-Y Please help .. if you could explain it in quite a simple way, thanks.
You need to isolate the variable y to one side, hence, you need to subtract 4 both sides, such that:
`3x - 4 = 4 - 4 - y => 3x - 4 = -y`
You need to multiply by -1 both sides, such that:
`y = 4 - 3x`
Hence, the equation of the function `y = f(x)` is `y = -3x + 4` .
Since the leading coefficient negative, a = -3, the graph of the function is a line that descends from quadrant 2 to quadrant 4.
The graph intercepts `x` axis at `y = 0` , such that:
-3x + 4 = 0 => -3x = -4 => x = 4/3
The graph intercepts y axis at x = 0, such that:
f(0) = y = 4
Hence, the graph intercepts x and y axis at the points `(4/3,0)` and `(0,4)` and it extends from quadrant 2 to quadrant 4.
to find out the values of the variables in a linear equation in 2 variables, you need two equations.
in simpler words, since in the your question, the values of both x and y are unknown, u will need two equations to solve it.
as an example, take the following equations:
to solve this, add both the equations,
therefore, x= -3/2
then substitute this value of x in anyone of the equations.Lets take the first equation,
hence, x= -3/2 and y=13/4