Respuesta :

The given expressions written in standard form are;

A) 21 × 10⁷

B) 5 × 10²

This is about expression of given algebra in standard form making use of laws of indices.

A) We are given;

(7 × 10⁵) × (3 × 10²)

Now according to the law of indices, when we want to multiply 2 numbers with same bases and different exponents, we retain the bases and add the exponents.

Also, when we want to multiply 2 numbers with different bases and same exponent, we multiply the bases and retain the exponent.

Applying that to our question gives;

(7 × 3)¹ × (10)⁽⁵ ⁺ ²⁾

⇒ 21 × 10⁷

B) We are given;

(2 × 10⁵)/(4 × 10²)

According to the law of indices, when we want to divide 2 numbers with same bases and different exponents, we retain the bases and subtract the exponents.

Also, when we want to divide 2 numbers with different bases and same exponent, we divide the bases and retain the exponent.

Thus;

(2/4)¹ × (10)⁽⁵ ⁻ ²⁾ = 0.5 × 10³

0.5 can also be expressed as; 5 × 10⁻¹

Thus, 5 × 10⁻¹ × 10³ = 5 × 10²

Read more at; brainly.in/question/18681990