a)
[tex]x = 11 - 2y[/tex]
[tex]8x = - 2 + 2y = > \times \frac{ - 2 + 2y}{8} = \frac{ - 1 + y}{4} [/tex]
[tex]11 - 2y = \frac{ - 1 + y}{4} = > 44 - 8y = - 1 + y[/tex]
[tex]9y = 45 = > y = 5[/tex]
[tex]x = 11 - 10 = 1[/tex]
b)
[tex]x = - 10 - 3y[/tex]
[tex]x = 5 + 2y[/tex]
[tex] - 3 - 3y = 5 + 2y[/tex]
[tex]5y = - 8[/tex]
[tex]y = - \frac{8}{5} = - 1.6[/tex]
[tex]x = 1.8[/tex]
c)
[tex]x = \frac{7.5 + 3y}{2} [/tex]
[tex]x = \frac{9 + y}{5} [/tex]
[tex] \frac{9 + y}{5} = \frac{7.5 + 3y}{2} [/tex]
[tex]18 + 2y = 37.5 + 15y[/tex]
[tex] - 19.5 = 13y[/tex]
[tex]y = 1.5[/tex]
[tex]x = 5.25[/tex]
COROANA?
;))
