25a²-10a+1+丨4b+1丨=0,求：[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)

25a²-10a+1+丨4b+1丨=0,求：[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)
25a²-10a+1+丨4b+1丨=0,求：[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)

25a²-10a+1+丨4b+1丨=0,求：[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)
25a²-10a+1+丨4b+1丨=0
(5a-1)²+丨4b+1丨=0
由非负性
5a-1=0
4b+1=0
得
a=1/5
b=-1/4
[(4a+3b)(4a-3b)-(2a-5b)(8a+5b)]÷(-2b)
=(16a²-9b²-16a²+30ab+25b²)÷(-2b)
=-8b-15a
=2-3
=-1