Use substitution to write an equivalent quadratic equation.

[tex]\[
(3x+2)^2 + 7(3x+2) - 8 = 0
\][/tex]

A. [tex]\( u^2 + 7u - 8 = 0 \)[/tex], where [tex]\( u = (3x+2)^2 \)[/tex]

B. [tex]\( u^2 + 7u - 8 = 0 \)[/tex], where [tex]\( u = 3x+2 \)[/tex]

C. [tex]\( u^2 + 7u - 8 = 0 \)[/tex], where [tex]\( u = 7(3x+2) \)[/tex]

D. [tex]\( u^2 + u - 8 = 0 \)[/tex]



Answer :

Certainly! Let's tackle the given problem step-by-step.

We are given the equation:
[tex]\[ (3x + 2)^2 + 7(3x + 2) - 8 = 0 \][/tex]

We will use substitution to simplify this equation. Let's choose a substitution to make the equation easier to handle.

Define [tex]\( u \)[/tex] as:
[tex]\[ u = 3x + 2 \][/tex]

Now, substitute [tex]\( u \)[/tex] back into the equation. The given equation simplifies to:
[tex]\[ u^2 + 7u - 8 = 0 \][/tex]

Hence, the equivalent quadratic equation in terms of [tex]\( u \)[/tex] is:
[tex]\[ u^2 + 7u - 8 = 0 \][/tex]

Remember that [tex]\( u = 3x + 2 \)[/tex]. Therefore, we have successfully written the equivalent quadratic equation as:
[tex]\[ u^2 + 7u - 8 = 0, \quad \text{where} \quad u = 3x + 2 \][/tex]

To summarize, the appropriate substitution results in:
[tex]\[ \boxed{u^2 + 7u - 8 = 0, \quad \text{where} \quad u = 3x + 2} \][/tex]

This correctly captures the transformed form of the original equation.