Simplify $(2^{2015})(5^{2019})$

Question

Question : $(2^{2015})$$(5^{2019})$

How do I simplify/solve that without a calculator? I have no idea how to continue, I know it's important to get the Base number the same so I can add the exponents. I'd appreciate it if someone could teach me how to do this, without a calculator.

I also tried to do it algebraically by letting $x$ $=$ $2015$ and thus

$$ (2^x)(5^{x+4}) $$

but having trouble simplifying any further as I cannot get the same base..

Answer 1

I believe that you can reduce the expression as follows:

$2^{2015}\cdot5^{2019}$

$=2^{2015}\cdot5^{2015+4}$

$=2^{2015}\cdot5^{2015}\cdot5^{4}$

$=(2\cdot5)^{2015}\cdot5^4$

$=625\cdot10^{2015}$ $=6.25\cdot 10^{2017}$

Answer 2

$$2^{2015}\cdot5^{2019} = 2^{2015}\cdot 5^{2015}\cdot 5^{4}=(2\cdot5)^{2015}\cdot 5^4$$

$$=10^{2015}\cdot (625)$$