You have the system: { 7x - 2y = 5 ; 14x - 4y = 10 }. Explain the best first step and why substitution or elimination helps reveal the nature of the system before isolating any variable.

Isolate y from the first equation and substitute into the second to find a unique solution; substitution always yields a unique intersection, even for multiples

Conclude the system is inconsistent and has no solution because the second equation has larger coefficients and therefore cannot match the first equation's points

Eliminate by subtracting the two equations to obtain a new equation with nonzero coefficients, then solve for both variables normally because dependencies are only discovered after solving

Recognize that the second equation is 2 times the first, so they represent the same line; do not isolate — conclude there are infinitely many solutions (dependent system)