Question

-x-3y=14
x=4y


solve using substitution

Answer 1

using
f1(x)= -x=3t =14

with f2(x) as x=4y

f1(f2)= -x-3y=14
F1(4y)= -(4y)-3y=14
= -4y-3y=14
= - 7y=14
= y= -2

Using the value of y, solve fo rx by entering the value in the original form of f1 or f2

-x-3y=14
-x-3(-2)=14
-x+6=14
x=-8

OR
x=4y
=4(-2)
= -8

Thus the solution is (x,y) = (-8,-2)

Answer 2

Solve both equations for one variable. Since the second equation is already solved for
`x`, we'll solve the other one for
`x`.


`x=-14-3y` and
`x=4y` are our two equations.

Now we can assume that if
`x = -14-3y` and
`x=4y`, we can assume that
`-14-3y = 4y`. If we solve for
`y`, we get that
`y=-2`. Plug in
`y=-2` into either one of the equations, I'll use
`x=4y`.
`x=4(-2)` so [/tex]x=-8[/tex]. Know we know what
`x` and
`y` are, so we can put it in an orderned pair: (-8,-2)