Question

qual o valor da incógnita "7x+y=0" "x+y=12"?

Answer 1

7x+y=0

x+y=12 (-1)

7x+y=0

-x-y=-12

6x=-12

x=-2

y=12-x

y=12-(-2)

y=12+2

y=14

S={(-2, 14)}