题目对于实数mmm,nnn,先定义一种新运算"⊗\otimes⊗"如下:m⊗n={m2+m+n,当m＞n时n2+m+n,当m≤n时m\otimes n=\left\{{\begin{array}{l}{{m^2}+m+n,当m＞n时}\\{{n^2}+m+n,当m≤n时}\end{array}}\right.m⊗n={m2+m+n,当m＞n时n2+m+n,当m≤n时,若x⊗(−1)=5x\otimes \left(-1\right)=5x⊗(−1)=5,则实数xxx的值为____.知识点：二次根式的加减法章节：数与式 / 二次根式
