Q. \(\;3x^2 + 30x + 75 =\;\)
Answer
Factor the quadratic:
\[
3x^2+30x+75=3(x^2+10x+25)=3(x+5)^2
\]
So the expression equals \(3(x+5)^2\).
Detailed Explanation
We want to solve the equation:
\[
3x^2 + 30x + 75 = 0
\]
Step 1: Check whether the quadratic can be factored.
Notice every term is divisible by 3:
\[
3x^2 + 30x + 75 = 3(x^2 + 10x + 25)
\]
So the equation becomes:
\[
3(x^2 + 10x + 25)=0
\]
Step 2: Find roots by setting the factor equal to zero.
Since \(3 \neq 0\), the product is zero only if the other factor is zero:
\[
x^2 + 10x + 25 = 0
\]
Step 3: Factor the trinomial as a perfect square.
We check whether \(x^2 + 10x + 25\) matches the form \((x+a)^2\).
Recall:
\[
(x+a)^2 = x^2 + 2ax + a^2
\]
Match coefficients:
- \(2a = 10\) so \(a = 5\)
- \(a^2 = 25\), which matches the constant term
Therefore, the trinomial is a perfect square:
\[
x^2 + 10x + 25 = (x+5)^2
\]
Step 4: Set the squared factor equal to zero.
\[
(x+5)^2 = 0
\]
Step 5: Take the square root of both sides.
The square is zero only when the inside is zero:
\[
x+5 = 0
\]
Step 6: Solve for \(x\).
\[
x = -5
\]
Final Answer:
\[
x = -5
\]
Algebra FAQ
What is the quadratic equation \(3x^2+30x+75=0\) factored as?
What is the discriminant of \(3x^2+30x+75=0\)?
Solve \(3x^2+30x+75=0\) for \(x\).
How do you solve \(3x^2+30x+75=0\) using the quadratic formula?
What is the vertex of \(y=3x^2+30x+75\)?
Can you complete the square for \(3x^2+30x+75\)?
Type the equation to start.
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