Question

3) (3x - 2y) (3x +2y);​

Answer 1

Формула разности квадратов:

$(a-b)(a+b)=a^2-b^2$

Для заданного выражения получим:

$(3x - 2y) (3x +2y)=(3x)^2 - (2y)^2=3^2\cdot x^2-2^2\cdot y^2=\boxed{9x^2-4y^2}$

Answer 2

To expand the expression (3x - 2y)(3x + 2y), you can use the distributive property, also known as the FOIL method (First, Outer, Inner, Last). Here's how you can do it step by step:

(3x - 2y)(3x + 2y)

First, multiply the terms in the first set of parentheses with the terms in the second set of parentheses:

First: (3x * 3x) = 9x^2 Outer: (3x * 2y) = 6xy Inner: (-2y * 3x) = -6xy Last: (-2y * 2y) = -4y^2

Now, combine these results:

9x^2 + 6xy - 6xy - 4y^2

The middle terms (6xy and -6xy) cancel each other out, so you're left with:

9x^2 - 4y^2

So, the expanded expression is:

9x^2 - 4y^2