Solution - Base conversion

$${\left(2E9\right)}_{16}$$

Expand digits with place-value powers in the source base.

$$2\cdot {16}^2+14\cdot {16}^1+9\cdot {16}^0$$

Sum the expanded terms to obtain the base-10 value.

$$745$$

Expand each digit by place value: $$2·{16}^2$$
+ $$14·{16}^1$$
+ $$9·{16}^0$$. This gives $$745$$ in base 10.

$$745\left(base10\right)$$

Use repeated division by the target base.

$$\frac{745}{10}$$

Record quotient and remainder for this division cycle.

$$745=10\cdot 74+5$$

Record quotient and remainder for this division cycle.

$$74=10\cdot 7+4$$

Record quotient and remainder for this division cycle.

$$7=10\cdot 0+7$$

Read remainders from last to first to form target-base digits.

$$745$$

Final converted representation in the target base.

$${\left(745\right)}_{10}$$

Repeatedly divide $$745$$ by $$10$$, collect remainders, and read them in reverse to get $$745$$.