Factor the high-degree polynomial expression 7x^2+42x+63=0 then solve for x

1 answer

Let's start by factoring the polynomial expression \( 7x^2 + 42x + 63 = 0 \).

First, we can factor out the greatest common factor (GCF), which is 7:

\[ 7(x^2 + 6x + 9) = 0 \]

Now, we can focus on the quadratic expression \( x^2 + 6x + 9 \). We will factor this expression. We can rewrite it as:

\[ x^2 + 6x + 9 = (x + 3)(x + 3) = (x + 3)^2 \]

So the equation now looks like this:

\[ 7(x + 3)^2 = 0 \]

Next, we can set this equation to zero:

\[ (x + 3)^2 = 0 \]

To solve for \( x \), we take the square root of both sides:

\[ x + 3 = 0 \]

Subtracting 3 from both sides gives us:

\[ x = -3 \]

Thus, the solution to the equation \( 7x^2 + 42x + 63 = 0 \) is:

\[ \boxed{-3} \]