Question

Me ajudemmm Dou 17 pontos

Answer 1

$a)x + y = 12 \\ \: \: \: \: x - y = 28 \\ \\ 2x = 40 \\ <strong>x = 20</strong> \\ \\ x - y = 28 \\ 20 - y = 28 \\<strong> y = - 8</strong> \\ \\ b)x + y = 24 \\ \: \: \: x - y = 18 \\ \\ 2x = 42 \\ <strong>x = 21</strong> \\ \\ x + y = 24 \\ 21 + y = 24 \\ <strong>y = 3</strong> \\ \\ c)x + y = 18 \\ \: \: \: x - y = 16 \\ \\ 2x = 34 \\ <strong>x = 17 </strong>\\ \\ x + y = 18 \\ 17 + y = 18 \\<strong> y = 1</strong> \\ \\ d)x + y = 14 \\ \: \: \: \: x - y = 20 \\ \\ 2x = 34 \\<strong> x = 17</strong> \\ \\ x + y = 14 \\ 17 + y = 14 \\ <strong>y = - 3</strong> \\ \\ e)x + y = 36 \\ \: \: \: \: x - y = 48 \\ \\ \\ 2x = 84 \\<strong> x = 42</strong> \\ \\ x + y = 36 \\ 42 + y = 36 \\<strong> y = - 6 </strong>\\ \\ f)x + y = 51 \\ \: \: \: \: x - y = 49 \\ \\ 2x = 100 \\ <strong>x = 50</strong> \\ \\ x + y = 51 \\ 50 + y = 51 \\ <strong>y = 1</strong>$

Qualquer dúvida, é só perguntar, jovem.

Answer 2

Resposta:

A. x= 20, y= -8

B. x= 21, y= 3

C. x= 17, y= 1

D. x= 17, y= -3

E. x= 42, y= -6

F. x= 50, y= 1

Explicação passo-a-passo:

A. y= 12 -x

x - (12 - x)= 28

x -12 +x = 28

2x = 28 + 12

2x = 40

x = 40/2 = 20

y= 12 -(20)

y= -8

B. -y= 18 -x (.-1)

y= -18 +x

x + (-18 + x)= 24

2x = 24 + 18

2x = 42

x = 42/2

x= 21

y= -18 +(21)

y= 3

C. -y = 16 -x (.-1)

y= -16 +x

x + (-16 + x)= 18

2x = 28 + 16

x = 34/2 = 17

y= -16 +(17)

y= 1

D.y= -20 + x

x+ (-20 + x)= 14

2x= 14 + 20

x= 34/2 = 17

y= -20 +(17)

y= -3

E. y= -48 +x

x +(-48 + x)= 36

2x= 36 + 48

x= 84/2 = 42

F. y= -49 +x

x + (-49 + x)= 51

2x = 49 + 50

x= 100/2 = 50

y= -49 +(50)

y= 1

É isso! Verifiquei todas as respostas!

Espero que isso ajude!