Jack, Sarah and Elena have to find which of the expressions are equivalent to each other. Expression A: 5x - 2x - 3
Expression B: 15x - 3
Expression C: 2x + x - 3
Elena says all three are equivalent because when she substitutes x with zero, all expressions equal -3.
ELENA IS INCORRECT **Answer the following on a loose leaf sheet of paper.**
• Identify the error in Elena's thinking.
Determine which of the expressions are equivalent.
Explain and show your process in determining which expressions are equivalent.