Question

18x+ 5y= 11
12x + 11y=31

(Método de suma y resta)​

Answer 1

a)18x+5y=11

18x=11-5y

x=(11-5y)/18

18*(11-5y)/18+11y=31

(198-90y)/18+11y=31

11-5y+11y=31

6y=42

y=7

b)12x+11y=31

12x=31-11y

x=(31-11y)/12

12*(31-11y)/12+11y=31

(372-132y)/12+11y=31

31-11y+11y=31

31-22y=31

22y=31-31

22y=0

y=0