Q. \(x^2 – x – 6 = 0\)
Answer
We solve \(x^2-x-6=0\) by factoring.
\(x^2-x-6=(x-3)(x+2)\), so
\((x-3)(x+2)=0 \Rightarrow x-3=0 \text{ or } x+2=0.\)
Thus \(x=3\) or \(x=-2\).
Final answer: \(x=3,\,-2\).
Detailed Explanation
We want to solve the equation
\[
x^2 – x – 6 = 0
\]
This is a quadratic equation, so we look for ways to factor it (or use the quadratic formula). Since it has nice integers, factoring is the fastest method.
Step 1: Identify the coefficients.
Compare
\[
x^2 – x – 6 = 0
\]
with the general form
\[
ax^2 + bx + c = 0
\]
Here:
- \(a = 1\)
- \(b = -1\)
- \(c = -6\)
Step 2: Factor the quadratic.
Factor the expression \(x^2 – x – 6\) into two binomials of the form
\[
(x + m)(x + n)
\]
where \(m\) and \(n\) are integers.
For the product to match:
- \(m \cdot n = -6\)
- \(m + n = -1\) (because the middle term is \(-x\))
Step 3: Find integers that satisfy both conditions.
List factor pairs of \(-6\):
- \(-1\) and \(6\) gives sum \(5\)
- \(1\) and \(-6\) gives sum \(-5\)
- \(-2\) and \(3\) gives sum \(1\)
- \(2\) and \(-3\) gives sum \(-1\)
The pair \(2\) and \(-3\) works because:
- \(2 \cdot (-3) = -6\)
- \(2 + (-3) = -1\)
Step 4: Write the factored form.
\[
x^2 – x – 6 = (x + 2)(x – 3)
\]
Step 5: Set each factor equal to zero.
Since the product is zero:
\[
(x + 2)(x – 3) = 0
\]
we get two equations:
\[
x + 2 = 0
\]
\[
x – 3 = 0
\]
Step 6: Solve each equation.
From \(x + 2 = 0\):
\[
x = -2
\]
From \(x – 3 = 0\):
\[
x = 3
\]
Final Answer:
\[
x = -2 \quad \text{or} \quad x = 3
\]
Graph
Algebra FAQ
What are the solutions to \(x^2-x-6=0\)?
How do you solve \(x^2-x-6=0\) by factoring?
How do you solve it using the quadratic formula?
What is the discriminant of \(x^2-x-6=0\)?
How many real solutions does the equation have?
What is the vertex of the parabola \(y=x^2-x-6\)?
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