已知关于xy的二元一次方程px+2y等于8,5x-6y等于-8,2x+5y-19等于o有公共解,求p的值
2019-04-13
已知关于xy的二元一次方程px+2y等于8,5x-6y等于-8,2x+5y-19等于o有公共解,求
p的值
优质解答
px+2y=8,3px+6y=24
5x-6y=4,3px+5x=28
2x+5y-8=0,4x+10y=16
px+2y=8,5px+10y=40,5px-4x=24
(1)3px+5x=28,
(2)5px-4x=24,
(1)/(2)得：（3p+5)/5p-4)=7/6
35p-28=18p+30
17p=58
p=58/17
px+2y=8,3px+6y=24
5x-6y=4,3px+5x=28
2x+5y-8=0,4x+10y=16
px+2y=8,5px+10y=40,5px-4x=24
(1)3px+5x=28,
(2)5px-4x=24,
(1)/(2)得：（3p+5)/5p-4)=7/6
35p-28=18p+30
17p=58
p=58/17