2x2-3x-2/3=0 16x2-24x+9=0 x2-4倍根号2x+9=0 3x2+10=2x2+8x 用配方
问题描述:
2x2-3x-2/3=0 16x2-24x+9=0 x2-4倍根号2x+9=0 3x2+10=2x2+8x 用配方
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此方程无实数根
3x^2+10=2x^2+8x
x^2-8x+10=0
x^2-8x=-10
x^2-8x+4^2=4^2-10
(x+4)^2=6
x+4=±√6
x=±√6-4