Rewrite exponential expressions

**What is the value of $A$ when we rewrite $\left(\dfrac{5}{2}\right)\^{\Large x}+\left(\dfrac{5}{2}\right)\^{\Large x+3}$ as $A\cdot \left(\dfrac{5}{2}\right)\^{\Large x}$** ? $A=$ [[☃ numeric-input 1]]