Beginning & Intermediate Algebra
Substitution, because xx is already isolated, so plugging that expression into the first equation is direct and efficient
Graphing is the only accurate method because the presence of a fractional coefficient forces approximations in algebraic methods
Elimination, because both equations can be quickly placed in standard form and their coefficients are multiples of each other after scaling
Cross-multiplying both equations by each other's coefficients before deciding on a method will always be faster than immediate substitution