Question

determine a,b,x,y,sabendo que ( x+y 2a+b) = (3 -1)
2x-y a-b 0 7

Answer 1

(x+y, 2a+b) = (3, -1)
x+y = 3 (I)
2a+b = -1 (II)

(2x-y, a-b) = (0, 7)
2x-y = 0 (III)
a-b = 7 (IV)

2x-y = 0 (III)
2x = y
x = y/2

x+y = 3 (I)
y/2+y = 3
y + 2y = 6
3y = 6 --> y = 6/3 --> y = 2
x = y/2 --> x = 2/2 --> x = 1

2a+b = -1 (II)
a-b = 7 (IV)

a = 7+b
2.(7+b)+b = -1
14+2b+b = -1
3b = -1-14
3b = -15
b = -15/3
b = -5

a = 7+b
a = 7-5
a = 2

S: {a=2, b=-5, x=1, y=2}