Resumen
Ejercicio 1
\[5x + 5y = 20x \atop -2x + 2y = -28x\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
Ejercicio 2
\[x^2 + 2y^2 = 66 \atop -x + 2y = 6\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
Ejercicio 3
\[x^2 - y^2 = -9 \atop -x + 3y = 11\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
Ejercicio 4
\[x^2 - y^2 = 12 \atop -3x + y = 14\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]
\[x = \boxed{\phantom{\rule{2em}{1.2em}}}, y = \boxed{\phantom{\rule{2em}{1.2em}}}\]