细心算一算,你一定很棒.已知|a+2|+b-3=0,化简代数式后求值:[(2a+b)2-(b+2a)(2a-b)-6b]÷2b

2025-03-07 06:57:19
推荐回答(1个)
回答1:

∵|a+2|≥0,
b-3
≥0,且|a+2|+
b-3
=0,
∴|a+2|=0,
b-3
=0,
解得:a=-2,b=3,
[(2a+b)2-(b+2a)(2a-b)-6b]÷2b.
=[4a2+4ab+b2-(2a+b)(2a-b)-6b]÷2b
=[4a2+4ab+b2-(4a2-b2)-6b]÷2b
=(4ab+2b2-6b)÷2b
=2a+b-3,
当a=-2,b=3时,原式=2×(-2)+3-3=-4.