Rado Numbers of Regular Nonhomogeneous Equations

We consider Rado numbers of the regular equations $\mathcal{E}(b)$ of the form $$c_1x_1+c_2x_2+\dots+ c_{k-1}x_{k-1} = x_k + b,$$ where $b \in \mathbb{Z}$ and $c_i \in \mathbb{Z}^{+}$ for all $i$. We give the upper bounds and the sufficient condition for the lower bounds for $t$-color Rado numbers $r(\mathcal{E}(b);t)$ in terms of $r(\mathcal{E}(0);t)$ for both $b>0$ and $b<0$. We also give examples where the exact values of Rado numbers are obtained from these results.