Answer:

69.997668.

Step-by-step explanation:

To perform the indicated operations, let's take them one by one:

1. ³/₇ + ² = 18²

It seems that there might be a formatting issue with the equation. Could you please clarify the equation?

2. 4³ + 5 - 15.3 ÷ 3⁸

Let's break down and solve this expression step by step:

First, let's calculate the exponentiation:

4³ = 4 * 4 * 4 = 64

Next, let's perform the division:

15.3 ÷ 3⁸ = 15.3 ÷ (3 * 3 * 3 * 3 * 3 * 3 * 3 * 3)

= 15.3 ÷ 6561

= 0.002332001

Now, let's substitute the values back into the original expression:

4³ + 5 - 15.3 ÷ 3⁸ = 64 + 5 - 0.002332001

Finally, let's perform the addition and subtraction:

64 + 5 - 0.002332001 ≈ 69.997668

Therefore, the result of the expression 4³ + 5 - 15.3 ÷ 3⁸ is approximately 69.997668.