Identify the mathematical expressions and systems of equations presented in the image.

Mathematical Expressions and Systems:

• \[ - = 3 \]
• \[ \lambda = a \]
• \[ \begin{cases} x + 5\lambda = 2 \\ 3x + a\lambda = a \end{cases} \]
• \[ 2\lambda = 1 \]
• \[ 4\lambda = 5 \]
• \[ \begin{cases} 2x + 5\lambda = 5 \\ x + a\lambda = 1 \end{cases} \]
• \[ a = \lambda \]
• \[ \frac{1}{2} = y = 4 \]
• \[ 3\lambda = 5 \]
• \[ 6x = 3 + 3\lambda \]
• \[ 5x - 3\lambda - 1 = 0 \]
• \[ x + 4 - 3\lambda = 0 \]
• \[ \frac{3}{1}x = \lambda - 5 \]
• \[ 3x = \lambda + 5 \]
• \[ 5x + 2\lambda = 1 \]
• \[ + 10 = 6x \]
• \[ - 2\lambda = 5 \]
• \[ + 4\lambda - 1 = 0 \]