Question

A) (3a - b)² - (3a + b)²;6) (5x – 3y)² + 30xy;​

Answer 1

Ответ:

решение на фотографии

Answer 2

Let's simplify the given expressions:

A) (3a - b)² - (3a + b)²:

First, let's expand both squares:

(3a - b)² = (3a - b)(3a - b) = 9a² - 6ab + b² (3a + b)² = (3a + b)(3a + b) = 9a² + 6ab + b²

Now, subtract the second expression from the first:

(9a² - 6ab + b²) - (9a² + 6ab + b²)

When you subtract, you change the sign of each term in the second expression:

9a² - 6ab + b² - 9a² - 6ab - b²

Now, combine like terms:

(9a² - 9a²) + (-6ab - 6ab) + (b² - b²)

The terms (9a² - 9a²) and (b² - b²) both equal zero. So, you're left with:

-12ab

So, the simplified expression is -12ab.

6. (5x - 3y)² + 30xy:

First, let's expand the square:

(5x - 3y)² = (5x - 3y)(5x - 3y) = 25x² - 15xy - 15xy + 9y² = 25x² - 30xy + 9y²

Now, add 30xy to this expression:

25x² - 30xy + 9y² + 30xy

When you add, the terms -30xy and +30xy cancel each other out:

25x² + 9y²

So, the simplified expression is 25x² + 9y².