问题标题:
【2x2-3x-2/3=016x2-24x+9=0x2-4倍根号2x+9=03x2+10=2x2+8x用配方】
问题描述:
2x2-3x-2/3=016x2-24x+9=0x2-4倍根号2x+9=03x2+10=2x2+8x用配方
何庆红回答:
2x^2-3x-2/3=0
x^2-(3/2)x-2/6=0
x^2-(3/2)x=2/6=1/3
x^2-(3/2)x+(3/4)^2=1/3+(3/4)^2
(x-3/4)^2=43/48
x-3/4=±√(43/48)=±√129/12
x=±(√129+9)/12
16x^2-24x+9=0
x^2-(3/2)x+9/16=0
x^2-(3/2)x+(3/4)^2=0
(x-3/4)^2=0
x=3/4
x^2-4√2x+9=0
b^2-4ac=(4√2)^2-4*9=-4
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