Q. \(x^2+6x-16=0\)
Answer
We solve the quadratic equation \(x^2+6x-16=0\) by factoring. Find numbers that multiply to \(-16\) and add to \(6\): \(8\) and \(-2\). So
\[
x^2+6x-16=(x+8)(x-2)=0
\]
Set each factor equal to zero:
\[
x+8=0 \Rightarrow x=-8,\quad x-2=0 \Rightarrow x=2
\]
Final result: \(x=-8\) or \(x=2\).
Detailed Explanation
We want to solve the quadratic equation
\[
x^{2}+6x-16=0
\]
Step 1: Identify the values of \(a\), \(b\), and \(c\).
A quadratic equation in standard form looks like
\[
ax^{2}+bx+c=0
\]
Here:
- \(a=1\)
- \(b=6\)
- \(c=-16\)
Step 2: Use the quadratic formula.
The quadratic formula is
\[
x=\frac{-b\pm\sqrt{b^{2}-4ac}}{2a}
\]
Substitute \(a=1\), \(b=6\), and \(c=-16\):
\[
x=\frac{-6\pm\sqrt{6^{2}-4\cdot 1\cdot (-16)}}{2\cdot 1}
\]
Step 3: Simplify inside the square root (the discriminant).
First compute \(6^{2}\):
\[
6^{2}=36
\]
Now compute \(-4ac\):
\[
-4\cdot 1\cdot (-16)=64
\]
So the discriminant is:
\[
b^{2}-4ac=36+64=100
\]
Step 4: Take the square root.
\[
\sqrt{100}=10
\]
Step 5: Substitute back into the quadratic formula.
\[
x=\frac{-6\pm 10}{2}
\]
Step 6: Split into two solutions.
First solution using \(+\):
\[
x=\frac{-6+10}{2}=\frac{4}{2}=2
\]
Second solution using \(-\):
\[
x=\frac{-6-10}{2}=\frac{-16}{2}=-8
\]
Final Answer:
\[
x=2 \quad \text{or} \quad x=-8
\]
Graph
Algebra FAQ
How do I factor \(x^2+6x-16=0\)?
What are the solutions using factoring?
How do I use the quadratic formula?
What is the discriminant and what does it tell me?
Can I solve by completing the square?
Quick check: do \(x=2\) and \(x=-8\) satisfy the equation?
Check roots and show steps clearly
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