Question

291. 1) (a-b) (a+b) (a – 3b);2) (a+b) (a - b)(a + 3b);​

Answer 1

Ответ и Объяснение:

Нужно знать формулу сокращённого умножения:

(x-y)·(x+y) = x² - y².

Решение.

1) (a-b)·(a+b)·(a-3·b)=(a²-b²)·(a-3·b)=a³-3·a²·b-a·b²+3·b³;

2)(a+b)·(a-b)·(a+3·b)=(a²-b²)·(a+3·b)=a³+3·a²·b-a·b²-3·b³.

Answer 2

It appears you've provided two algebraic expressions, and you may want to simplify them or perform some operations on them. Let's work with each expression one by one:

1. (a - b) (a + b) (a - 3b):

To simplify this expression, you can use the distributive property to multiply the terms:

(a - b) (a + b) (a - 3b) = (a^2 + ab - ab - b^2) (a - 3b)

Now, simplify further by combining like terms:

(a^2 - b^2) (a - 3b)

This expression can be simplified even further using the difference of squares identity (a^2 - b^2 = (a + b)(a - b)):

(a + b)(a - b)(a - 3b)

So, the simplified expression is (a + b)(a - b)(a - 3b).

2. (a + b) (a - b) (a + 3b):

Similarly, we can simplify this expression using the distributive property:

(a + b) (a - b) (a + 3b) = (a^2 - b^2) (a + 3b)

Again, you can apply the difference of squares identity:

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

So, the simplified expression is:

(a + b)(a - b)(a + 3b)

Both expressions are now simplified, and you have the final results.