已知|a-4|+b²+4=4b,求a²-ab÷a²-b²的值.
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已知|a-4|+b²+4=4b,求a²-ab÷a²-b²的值.
已知|a-4|+b²+4=4b,求a²-ab÷a²-b²的值.
已知|a-4|+b²+4=4b,求a²-ab÷a²-b²的值.
|a-4|+b²+4=4b
|a-4|+b²-4b+4=0
∴|a-4|+(b-2)²=0
∴a-4=0
b-2=0
∴a=4
b=2
(a²-ab)÷(a²-b²)
=a(a-b)/(a+b)(a-b)
=a/(a+b)
=4/(4+2)
=2/3
|a-4|+b²+4=4b
|a-4|+b²+4-4b=0
|a-4|+(b-2)²=0
a-4=0,b-2=0
a=4,b=2
a²-ab÷a²-b²
=16-8÷16-4
=12-0.5
=11.5
|a-4|+b²+4=4b
|a-4|+(b-2)²=0
|a-4|>=0,(b-2)²>=0(都为非负数)
|a-4|=0,(b-2)²=0
a=4,b=2
a²-ab÷a²-b²=a²-b/a-b²=16-2/4-4=23/2