Question

me ajudem por favor so o desenvolvimento ​

Answer 1

7)

x=3y=11 ==> x=11-3y  (i)

2x-y=1 (ii)

(i)  em (ii)  

2*(11-3y)-y=1  ==>22-6y-y=1 ==>y=-21/(-7)=3  

Usando (i)==>x=11-3*3=2

8)

2x+y=8 ==> x=(8-y)/2   (i)

3x+2y=7 (ii)

(i) em (ii)

3*(8-y)/2 +2y=7

3*(8-y) +4y=14

24-3y+4y=14

y=14-24

y=-10  

Usando (i) ==> x=(8-(-10))/2=18/2=9

9)

x/3-y/2=1

2x-3y=6  ==>x=(6+3y)/2   (i)

-2x+y/3=2 (ii)

(i)  em (ii)

-2*(6+3y)/2 +y/3=2

-3*(6+3y)+y=6

-18-9y+y=6

-8y=24

y=-3

Usando (i)  ==> x=(6-9)/2 =-3/2

10)

x-y=6 ==> x=6+y (i)

-2x+y/2=3 (ii)

(i) em (ii)

-2*(6+y) +y/2 =3

-4*(6+y)+y=6

-24-4y+y=6

-3y=30

y=-10

Usando (i) ==> x=6-10=-4