Question

resolva os sistemas:

A) x+y = 60

5x - y = 210


B) x+y = 78

x+2y = 110


C) 2x/3 = y/2 + 4

x+y = 48


D) 2x + y = 13

4x + 3y = 32​

Answer 1

Resposta:

Está faltando a C, desculpe

Explicação passo a passo:

A) x+y = 60

5x - y = 210

_________________

(x = 60 -y)

5x - y = 210

5. (60 -y) - y= 210

300 - 5y -y =210

300 -6y =210

-6y = 210 -300

-6y = -90.(-1)

y = 90/6

y=15

x + 15 = 60

x =60 -15

x= 45

________________

B) x+y = 78

x+2y = 110

_______________

(x = 78-y)

78 -y +2y = 110

y = 110 -78

y = 32

x+32 = 78

x =78 -32

x= 46

________________

D) 2x + y = 13

4x + 3y = 32​

____________

(y = 13 -2x)

4x + 3. (13-2x) = 32​

4x + 39 - 6x =32

-2x = 32 -39

-2x = -7 .(-1)

x = 7/2 ou 3,5

2x + y = 13

2. (7/2) + y = 13

(14/2) + y =13

y = 13 - 7

y = 6