Question

(C) 3x-2y=55
X+y=140

(D) 55x+140y=3
3x-2y=55

Answer 1

Resposta:

c) (x,y)= (67,73)

d) (x,y)= (3853/265 , - 1508/265)

Explicação passo-a-passo:

a)

{3x-2y=55

{x+y=140

↓

{3x-2y=55

{x=140-y

↓

3(140-y)-2y=55

↓

y=73

↓

x=140-73

↓

x=67

↓

(x,y)= (67,73)

d)

{55x+140y=3

{3x-2y=55

↓

{55x+140y=3

{x=55/3 + 2/3 y

↓

55(55/3 + 2/3 y)+140y=3

↓

y= - 1508/265

↓

x= 55/3 + 2/3 (-1508/265)

↓

x= 3853/265

↓

(x,y)= (3853/265 , - 1508/265)

Answer 2

c) X=140-y joga na primeira

3(140-y)-2y=55. 420-3y-2y=55

-5y=55-420. y=365/5 y=73 x=67