Question

1- Resolva

X-Y=2
X.Y=6

Answer 1

Resolvendo as equacao do sistema :
{ X - Y = 2 <> X = 2 + Y........A
{ X . Y = 6...........B

Fazendo A com B
~~~~~~~~~~~~~~~~
X . Y = 6
(2 + Y) .Y = 6
2Y + Y^2 = 6
Y^2 + 2Y = 6
Y^2 + 2Y - 6 = 0
a = 1 ; b = 2 ; c = -6

Formula delta
~~~~~~~~~~~~
D = b^2 - 4 a c

D = (2)^2 - 4 (1) (-6)

D = 4 - 4(-6)

D = 4 + 24

D = 28

Formula da braskara
~~~~~~~~~~~~~~~~~~
Y = - b + ; - \/D
......._________
................2a

Y = - (2) + ; - \/28
........__________
.................2(1)

Y = - 2 + ; - 5,29
.......__________
.................2

Y1 = - 2 + 5,29
.........________
................2

Y1 = 3,29 / 2

Y1 = 1,645

Y1 = 1,65

xxxxxxxxxxxxxxxxx

Y2 = - 2 - 5,29
.........._______
...................2

Y2 = - 7,29
.........._____
...............2

Y2 = 3,645

Y2 = 3,65

s = ( 1,65 ; 3,65 )