Linear in data / parameters

Problem

For each model, determine if it is linear in data and/or linear in parameters?

1. \(y_i=β_2x_{2i}x_{3i}+ε_i\)
2. \(y_i=β_1+β_1^2x_{3i}+ε_i\)
3. \(y_i={\left( β_2x_i \right)}^2+ε_i\)
4. \(y_i=β_2x_{2i}+β_3x_{3i}+ε_i\)
5. \(y_i=β_2log x_{2i}+β_3e^{x_{3i}}+ε_i\)