Index Notation Question

Question

I wanted to know if someone could help me with this, please.

This is my progress so far with the question:

$N = 2\times 5^3\times x^4$

$N = 250x^4$

$N^2 = (250x^4)^2$

$N^2 = 62500x^8$

$5N^2 = 5(62500x^8)$

$5N^2 = 312500x^8$

Thanks

Answer 1

$$N = 2 \times 5^3 \times x^4$$

$$N^2 = 2^2 \times 5^6 \times x^8$$

$$5N^2 = 2^2 \times 5^{6+1} \times x^8$$

$$5N^2 = 2^2 \times 5^{7} \times x^8$$

We do not have to multiply a number out explicitly.