化简求值:已知|2a-1|+b?3=0,化简代数式后求值:[(2a+b)2-(2a-b)(2a+b)-8b]÷2b

2025-04-15 16:44:24
推荐回答(1个)
回答1:

|2a-1|+

b?3
=0,
∵2a-1≥0,
b?3
≥0,
又∵|2a-1|+
b?3
=0,
∴2a-1=0,b-3=0,
∴a=
1
2
,b=3,
∴[(2a+b)2-(2a-b)(2a+b)-8b]÷2b
=[4a2+4ab+b2-4a2+b2-8b]÷2b
=(4ab+2b2-8b)÷2b
=2a+b-4,
把a=
1
2
,b=3代入得:原式=2×
1
2
+3-4=0.