X+5y+1=3X-2y-14=0

x+5y+1=3x-2y-14=0

其實就是

{ x + 5y + 1 = 0 --- ( 1 )

{ 3x - 2y - 14 = 0 --- ( 2 )

( 1 ) x 3 : 3x + 15y + 3 = 0

( 1 ) x 3 - ( 2 ): 3x + 15y + 3 - 3x + 2y + 14 = 0

17y + 17 = 0

17y = -17

y = -1

x + 5 ( - 1 ) + 1 = 0 [式1]

x = 5 - 1 = 4

所以x = 4, y = -1。

X+5y+1=3X-2y-14=0
can be written as
{X+5y+1=0........(1)
{3X-2y-14=0 ......(2)

from (1)
we have
x=-1-5y....(3)

sub (3)into (2)
3(-1-5y)-2y-14=0
-3-15y-2y-14=0
-17y=17
y=-1
sub y=-1 into (3)
x=-1-5(-1)
x=4

2007-10-03 22:15:09 補充：
or use this method{X 5y 1=0........(1){3X-2y-14=0 ......(2)(1)x3, 3x 15y 3=0.......(3)(3)-(2),17y 17=0 y=-1sub y=-1 into (1)x 5(-1) 1=0x=4

X+5y+1=0 (1)
3X-2y-14=0 (2)
(1)
3x+15y+3=0 (3)
(3)-(1)得
17y+17=0
17y=-17
y=-1
y=-1代入(1)
x-5+1=0
x=4

x=4
y=-1