Question

Determine o valor de X e Y nos sistemas abaixo:

a) 3x+y=3 
9x-2y=1    

b) 12x+20y=44  
  -12x+9y=15  
 
c) 2x-y=0  
    x+y=15 

Answer 1

a) 3. 1 = -6-9= -15
9. -2

Δx= 3. 1
1. -2. = -6-1=-7


Δy= 3. 3
9. 1. = 3-27= -24

x= -7/-15. y= -8/-5




b) 12. 20
-12. 9 = 108+240=348



Δ x= 44. 20
15. 9 =396-300=96

Δy= 12. 44
-12. 15 = 180+528=708


x= 96/348. simplificando 8/29

y= 708/348. simplificando 59/29


c) 2. -1
1. 1. = 2+1=3


Δx= 0. -1
15. 1. = 0+15=15


Δy= 2. 0
1. 15 = 30-0= 30


x= 15/3 x=5
y= 30/3. x= 10