已知:实数x,y满足 根号2x-3y-1+ |x-2y+2| =0,求4x -5分之4y的值

问题描述:

已知:实数x,y满足 根号2x-3y-1+ |x-2y+2| =0,求4x -5分之4y的值

2x-3y-1=0
x-2y+2=0
=> x=8 ,y=5
4x-4y/5=28

2x-3y-1=0
x-2y+2=0
x=8 y=5
4x -5分之4y=20/27

实数x,y满足√2x-3y-1+ |x-2y+2| =0
因为√2x-3y-1与 |x-2y+2| 都≥0
所以,2x-3y-1=0
x-2y+2=0
y=5,x=8
4y/(4x-5)
=20/(32-5)
=20/27
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后面你写的不明确,或者是:
4x-(4y/5)
=32-(20/5)
=32-4
=28

根号2x- 3y -1 =0
|x-2y +2| = 0
2x -3y -1 =0 ①

x-2y +2 =0 ②
②*2 2x -4y +4=0 ③
③ - ① 得 :

y = 5
x =8
4x - 4y/5 = 4*8 - 4*5/5
= 32 -4 = 24