Question

6. Encontrexe y que determinam, em cada caso, a igualdade:
a) (x + y, x - 3y) = (3,7)
b) (x + 4, y - 1) = (5,3)​

Answer 1

a) (x + y, x - 3y) = (3,7)

x+ y = 3

x-3y = 7

D = -3-1= -4

Dx= -9 -7= -16

Dy=7-3 = 4

x= Dx/D

x= (-16)/(-4)

x=4

y=Dy/D

y=(4)/(-4)

y=-1

s={(4,-1)}

b) (x + 4, y - 1) = (5,3)

x+4=5

y-1=3

x=5-4

x=1

y=3+1

y=4

s={(1,4)}