X²+2X=99,
7个回答
原式可化简为:X²+2X-99=0
(x+1)²-100=0
(x+1)²=100
x+1=10或者x+1=-10
解得:x=9 或者x=-11
相关问题
2x+2x(99-x)=99
1x1+0x1+2x2+1x2+3x3+2x3+4x4+3x4……99x99+98x99+100x100+99x100
3x(1x2+2x3+3x4+……+99x100)= (A)97x98x99 (B)98x99x100 (C)99x 1
100X100—99X99+98X98+...+2X2—1X1
100X100-99X99-98X98-97X97+…+2X2-1X1=?
当X=-1时 求X+2X^2+3X^3+…+99^99+100X^100
计算100X100-99X99+98X98-97X97+...+2X2-1X1=
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