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

2 Answers
Alan P.
Jul 8, 2016

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.

Ratnaker Mehta
Jul 8, 2016

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.

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