La pregunta 6 por favor?

<img src="https://tex.z-dn.net/?f=%20%5Cbullet%20~~y%5E2%3D2%5Exy%2B2%5E%7B2x%2B1%7D%5C%5C%20%5C%5C%20y%5E2-2%5Exy-2%5E%7B2x%2B1%7D%3D0%5C%5C%20%5C%5C%20y%3D%5Cdfrac%7B2%5Ex%5Cpm%5Csqrt%7B%282%5Ex%29%5E2%2B4%282%5E%7B2x%2B1%7D%29%7D%7D%7B2%7D%5C%5C%20%5C%5C%20%5C%5C%20y%3D%5Cdfrac%7B2%5Ex%5Cpm2%5Ex%5Csqrt%7B1%2B8%7D%7D%7B2%7D%5C%5C%20%5C%5C%20%5C%5C%20y%3D%5Cdfrac%7B2%5Ex%5Cpm2%5Ex%5Ccdot%203%7D%7B2%7D%5C%5C%20%5C%5C%20%5C%5C%20y_1%3D-2%5Ex%5Cvee%20y_2%3D2%5E%7Bx%2B1%7D%5C%5C%20%5C%5C%20%5C%5C%20%5Ctext%7BPero%20como%20el%20dominio%20del%20logaritmo%2C%20sobre%20el%20campo%20de%20los%20n%5C%27umeros%7D%5C%5C%20%5Ctext%7Breales%20es%20positivo%20entonces%20%7Dy%3D2%5E%7Bx%2B1%7D%20" />

<img src="https://tex.z-dn.net/?f=%20%5Cbullet~~%20x%5E2%3D1%2B3%5Clog_2y%5C%5C%20%5C%5C%20%20x%5E2%3D1%2B3%5Clog_22%5E%7Bx%2B1%7D%5C%5C%20%5C%5C%20%20x%5E2%3D1%2B3%28x%2B1%29%5C%5C%20%5C%5C%20x%5E2-3x-4%3D0%5C%5C%20%5C%5C%20%28x-4%29%28x%2B1%29%3D0%5C%5C%20%5C%5C%20x_1%3D-1%5Cvee%20x_2%3D4%5Cto%20%5Cboxed%7By%3D2%5E%7Bx%2B1%7D%5Cin%5C%7B1%2C32%5C%7D%7D%5C%5C%20%5C%5C%20%5C%5C%20%5Ctextit%7BSoluci%5C%27on%20del%20sistema%3A%20%7D%28x%2Cy%29%5Cin%20%5C%7B%28-1%2C1%29%3B%284%2C32%29%5C%7D%20" />Respuesta : según las alternativas debería ser (a).