已知2x²-5-x与x²+3的值互为相反数,则x的值为(要解析)
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已知2x²-5-x与x²+3的值互为相反数,则x的值为(要解析)
已知2x²-5-x与x²+3的值互为相反数,则x的值为(要解析)
已知2x²-5-x与x²+3的值互为相反数,则x的值为(要解析)
互为相反数
则2x^2-5-x+x^2+3=0
3x^2-x-2=0
(3x+2)(x-1)=0
则3x+2=0或x-1=0
即x=-2/3或x=1
互为相反数
则2x^2-5-x+x^2+3=0
3x^2-x-2=0
(3x+2)(x-1)=0
则3x+2=0或x-1=0
即x=-2/3或x=1
2x²-5-x+x²+3=0
3x²-x-2=0
(x-1)(3x+2)=0
x=1 or x=-2/3
-2/3,1
互为相反数,则和为0,即2x²-5-x+(x²+3)=0
x²-x-2=(x-2)*(x+1)=0
则x-2=0或x+1=0
所以x=2或者x=-1
2x²-5-x+x²+3=0
3x²-x-2=0
(x-1)(3x+2)=0
x=1 或x=-2/3
既然互为相反数,根据相反数相加等于零,可得2x(2)-5-X+X(2)+3=0,解3x(2)-x-2=0,再根十字相乘法,得(x-1)(3x+2)=0,所以x=1或者x=-2/3.
备注:X(2)表示x的平方