Question

How do you solve the following linear system: #y = 3x+4 , y-3x=-2 #?

Answer 1

The given pair of equations has no solution(s).

Explanation:

If
[1]`color(white)("XXX")y=3x+4`
and
[2]`color(white)("XXX")y-3x=-2`

Substituting (from [1]) `3x+4` in place of `y` into [2]
[3]`color(white)("XXX")cancel(3x)+4-cancel(3x)=-2`

Since `4 != -2`
these equations are inconsistent.

Answer 2

The system has no soln. , or, the Soln. Set `=phi.`

Explanation:

Substituting the value of `y`, obtained from the first eqn., in the second eqn., we get,

`(3x+4)-3x=-2,` i.e., `4 = -2`, which is an impossible result!

Hence, the Soln. Set `=phi.`