Question

me ajudem no sistema de equações: a) 3x+6y=12 e 2x+6y=-10 b) 3x+y=3 e 9x-2y=1 c) x+y=5 e -2x+y=-1 obrigada ; )

Answer 1

a) 3x+6y= 12
2x+6y=-10
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3x+6y= 12
3x= 12-6y
x= (12-6y)/3

2x+6y= -10
2.(12-6y)/3+6y= -10
8-4y+6y= -10
2y= -10-8
2y= -18
y= -18/2
[y= -9]

x=(12-6y)/3
x= (12-6.(-9)/3
x= (12+54)/3
x= 66/3
[x= 22]

b) 3x+y= 3
9x-2y= 1
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3x+y= 3
(y= 3-3x)

9x-2y= 1
9x-2.(3-3x)= 1
9x-6+6x= 1
9x+6x= 1+6
15x= 7
[x= 7/15]

y= 3-3x
y= 3-3.7/15
[y= 16/10]










c) x+y= 5 e -2x+y= -1 x=5-y -2.(5-y)+1y= -1 -10+2y+1y= -1 3y= -1+10 3y= 9 y= 9/3 [y=3] x= 5-y x= 5-3 [x= 2] Espero ter ajudado!!!