x成上9等于18x等于几

x成上9等于18x等于几 -18x等于-9x x等于几 x、y等于几 X等于几? 未知数x等于几? x等于 几 x等于几? x是等于几 求x等于几 这题x等于几? 0x等于1,x等于几 x等于几Y等于几 4x-x等于几 7x*x等于几 几x几等于2400. 已知x加x加y等于十五,x加y等于9,x等于几?y等于几? x等于7,则x等于几 负x等于7,则x等于几 |X|=-x x等于几?为什么