Question

podem me ajudar com isso?​

Answer 1

6) a) x= 20 - y

3(20-y) + 4y= 72

60-3y +4y = 72

-3y +4y = 72 - 60

Y=12

X=20-12

X = 8

B)x+y = 11

X= y-11

Y-( 11-y) =3

Y-11+y=3

2y=3 + 11

2y=14

Y=14/2

Y =7

X=7-11

X= -4

C)X+y= 6

X = 6 -y

2(6-y) + y =4

12- 2y + y=4

-Y = 4 - 12

-Y= -8 (-1)

Y = 8

X=6 - 8

X= -2