5．已知函数f(x)={x2−4x+4,x⩽2kx−2k,x>2f(x)=\left\{\begin{array}{l}{{x}^{2}-4x+4,x\leqslant 2}\\ {kx-2k,x>2}\end{array}\right.f(x)={x2−4x+4,x⩽2kx−2k,x>2，方程f(x)−t=0f(x)-t=0f(x)−t=0有两个实数解，分别为x1x_{1}x1和x2x_{2}x2，当1<t<31<t<31<t<3时，若存在ttt使得x1+x2=4x_{1}+x_{2}=4x1+x2=4成立，则kkk的取值范围为((( )))