Which choice is the most efficient first step to solve this set of equations? 2x – x = y – y + 30 2x + x + y = y + 30 y + y = 30 x + 2x = 30

To solve this set of equations, the most efficient first step is to simplify each equation.

1. Start with the first equation: ( 2x – x = y – y + 30 ). This simplifies to ( x = 30 ).
2. For the second equation: ( 2x + x + y = y + 30 ). This can also be simplified by subtracting ( y ) from both sides.
3. The third equation: ( y + y = 30 ) simplifies to ( 2y = 30 ), which leads to ( y = 15 ) when solved.
4. Lastly, the fourth equation simplifies to ( 3x = 30 ), resulting in ( x = 10 ).

By simplifying them, you can easily identify values for ( x ) and ( y ) without any complex substitutions or combinations. This clear simplification is effective for solving these equations step by step.