Solve for a3 a_3=4(5)^(3-1)

$a_{3} = 4 {(5)}^{3 - 1}$

Step 1

Subtract $1$ from $3$ .

$a_{3} = 4 \cdot 5^{2}$

Step 2

Raise $5$ to the power of $2$ .

$a_{3} = 4 \cdot 25$

Step 3

Multiply $4$ by $25$ .

$a_{3} = 100$