Factor the following expressions:

[tex]\[
\begin{array}{ll}
3a^2 - 6a^2b & 2x^3 + 4x^2 + \\
10x - 5y + 35 & 3x^2y - 5
\end{array}
\][/tex]

Write the following as a polynomial:

[tex]\[
(x+3)(x+7) = (x+10) \quad (x-4)^2
\][/tex]



Answer :

Certainly! Let's go through each part of the problem step by step.

### Part 1: Factoring the given expressions

#### Expression 1
Given: [tex]\( 3a^2 - 6a^2b \)[/tex]

We can factor out the common term [tex]\( 3a^2 \)[/tex]:

[tex]\[ 3a^2 - 6a^2b = 3a^2(1 - 2b) \][/tex]

Thus, the factored form is:

[tex]\[ 3a^2(1 - 2b) \][/tex]

#### Expression 2
Given: [tex]\( 2x^3 + 4x^2 + 10x - 5y + 35 \)[/tex]

Notice that [tex]\( 2x^3, 4x^2, 10x \)[/tex] involve [tex]\( x \)[/tex], while [tex]\(-5y + 35\)[/tex] do not. We can first group the terms with [tex]\( x \)[/tex] and the constant terms separately:

[tex]\[ (2x^3 + 4x^2 + 10x) + (-5y + 35) \][/tex]

We can further factor the grouped terms:

For [tex]\( 2x^3 + 4x^2 + 10x \)[/tex], factor out the common factor [tex]\( 2x \)[/tex]:

[tex]\[ 2x(x^2 + 2x + 5) \][/tex]

For [tex]\(-5y + 35\)[/tex], factor out the common factor [tex]\(-5\)[/tex]:

[tex]\[ -5(y - 7) \][/tex]

Thus, the expression can be written as:

[tex]\[ 2x(x^2 + 2x + 5) - 5(y - 7) \][/tex]

#### Expression 3
Given: [tex]\( 3x^2y - 5 \)[/tex]

This expression cannot be factored further as it is already in its simplest form:

[tex]\[ 3x^2y - 5 \][/tex]

### Part 2: Writing as a polynomial

#### Polynomial 1
Given: [tex]\((x + 3)(x + 7)\)[/tex]

We can expand this polynomial:

[tex]\[ (x + 3)(x + 7) = x^2 + 7x + 3x + 21 = x^2 + 10x + 21 \][/tex]

So, the expanded polynomial is:

[tex]\[ x^2 + 10x + 21 \][/tex]

#### Polynomial 2
Given: [tex]\((x - 4)^2\)[/tex]

We can expand this polynomial using the formula [tex]\((a - b)^2 = a^2 - 2ab + b^2\)[/tex]:

[tex]\[ (x - 4)^2 = x^2 - 2 \cdot x \cdot 4 + 4^2 = x^2 - 8x + 16 \][/tex]

So, the expanded polynomial is:

[tex]\[ x^2 - 8x + 16 \][/tex]

In summary, the polynomials after expansion are:

[tex]\[ (x + 3)(x + 7) = x^2 + 10x + 21 \][/tex]

[tex]\((x - 4)^2 = x^2 - 8x + 16\)[/tex]

And factoring discussed:

1. [tex]\( 3a^2 - 6a^2b \)[/tex] simplifies to [tex]\( 3a^2(1 - 2b) \)[/tex]
2. [tex]\( 2x^3 + 4x^2 + 10x - 5y + 35 \)[/tex] simplifies to [tex]\( 2x(x^2 + 2x + 5) - 5(y - 7) \)[/tex]
3. [tex]\( 3x^2y - 5 \)[/tex] remains [tex]\( 3x^2y - 5 \)[/tex]