What is the solution set of the equation [tex]x^2 + 3x - 4 = 6[/tex]?

A. [tex]\{-5, 2\}[/tex]

B. [tex]\{-2, -1\}[/tex]

C. [tex]\{2, 7\}[/tex]

D. [tex]\{5, 10\}[/tex]



Answer :

To solve the quadratic equation [tex]\( x^2 + 3x - 4 = 6 \)[/tex], follow these steps:

1. Move all terms to one side of the equation to set it to zero:
[tex]\[ x^2 + 3x - 4 - 6 = 0 \][/tex]
Simplify:
[tex]\[ x^2 + 3x - 10 = 0 \][/tex]

2. Factor the quadratic equation [tex]\(x^2 + 3x - 10 = 0\)[/tex]:
To factor the quadratic expression, we need to find two numbers that multiply to [tex]\(-10\)[/tex] (the constant term) and add up to [tex]\(3\)[/tex] (the coefficient of the [tex]\(x\)[/tex] term).

The numbers that satisfy these conditions are [tex]\(5\)[/tex] and [tex]\(-2\)[/tex] because:
[tex]\[ 5 \times (-2) = -10 \quad \text{and} \quad 5 + (-2) = 3 \][/tex]

So, we can factor the equation as:
[tex]\[ (x + 5)(x - 2) = 0 \][/tex]

3. Solve the factored equation by setting each factor to zero:
[tex]\[ x + 5 = 0 \quad \text{or} \quad x - 2 = 0 \][/tex]

Solving these:
[tex]\[ x = -5 \quad \text{or} \quad x = 2 \][/tex]

4. Determine the solution set:
The solution set is:
[tex]\[ \{-5, 2\} \][/tex]

Considering the solution set, we match it with the given choices:

A. [tex]\(\{-5, 2\}\)[/tex]

B. [tex]\(\{-2, -1\}\)[/tex]

C. [tex]\(\{2, 7\}\)[/tex]

D. [tex]\(\{5, 10\}\)[/tex]

The correct option is:
[tex]\(\boxed{A}\)[/tex]