64x²-(16a+4b)x+ab=0 In the given equation, a and b are positive constants. The sum of the solutions to the given equation is k(4a+b), where k is a constant. What is the value of k ?
ANSWER:
161
Explanation:
Step 1: Understanding the Sum of Solutions Formula
For any quadratic equation of the form ax2+bx+c=0, the sum of its solutions is given by the formula:
−ab
Step 2: Identifying Coefficients in the Given Equation
The given equation is:
64x2−(16a+4b)x+ab=0
Here:
- The coefficient of x2 (which is a in the general formula) is 64.
- The coefficient of x (which is b in the general formula) is −(16a+4b).
Step 3: Calculating the Sum of Solutions
Using the formula for the sum of solutions:
−64−(16a+4b)=6416a+4b
Simplify this expression:
6416a+4b=164a+b
Step 4: Equating the Expression with k(4a+b)
According to the problem, this sum is equal to k(4a+b). So we have:
164a+b=k(4a+b)
Now, dividing both sides by 4a+b (assuming 4a+b=0):
k=161
Thus, the value of k is:
161
Extended Knowledge Points
What is the Sum of Solutions in a Quadratic Equation?
The sum of the solutions for any quadratic equation of the form ax2+bx+c=0 is given by −ab, where b is the coefficient of x and a is the coefficient of x2.
Quadratic Equations in General Form
A quadratic equation is typically written as ax2+bx+c=0, where a, b, and c are constants. The solutions of this equation can be found using various methods, including factoring, completing the square, or the quadratic formula.
Application of Constants in Quadratic Problems
In many quadratic problems, constants such as k represent proportionality or other scaling factors. Solving for these constants often requires equating terms or simplifying expressions to find the desired relationship.
Similar Questions:
Question 1:
25x2−(10m+5n)x+mn=0
In the given equation, m and n are positive constants. Find the value of k.
Answer:
The value of k is 1/5.
Explanation:
Step 1: Identify the Equation Type
The given equation is a quadratic equation:
25x2−(10m+5n)x+mn=0
For any quadratic equation Ax2+Bx+C=0, the sum of the solutions can be found with −AB.
Step 2: Define A and B
Here, we identify:
- A=25
- B=−(10m+5n)
Step 3: Calculate the Sum of Solutions
Using the sum of solutions formula:
Sum of solutions=−AB=−25−(10m+5n)=2510m+5n
Step 4: Simplify the Sum of Solutions
Simplify 2510m+5n as follows:
2510m+5n=255(2m+n)=52m+n
Thus, the sum of the solutions is 52m+n.
Step 5: Equate and Solve for k
According to the problem, the sum of the solutions is also k(2m+n). Therefore:
52m+n=k(2m+n)
Step 6: Isolate k
Dividing both sides by 2m+n (assuming 2m+n=0):
k=51
Question 2:
9x2−(6p+3q)x+pq=0
In the given equation, p and q are positive constants. Find the value of k.
Answer:
The value of k is 1/3.
Explanation:
Step 1: Identify the Equation Type
The given equation is a quadratic equation:
9x2−(6p+3q)x+pq=0
For any quadratic equation Ax2+Bx+C=0, the sum of the solutions can be found with −AB.
Step 2: Define A and B
Here, we identify:
- A=9
- B=−(6p+3q)
Step 3: Calculate the Sum of Solutions
Using the sum of solutions formula:
Sum of solutions=−AB=−9−(6p+3q)=96p+3q
Step 4: Simplify the Sum of Solutions
Simplify 96p+3q as follows:
96p+3q=93(2p+q)=32p+q
Thus, the sum of the solutions is 32p+q.
Step 5: Equate and Solve for k
According to the problem, the sum of the solutions is also k(2p+q). Therefore:
32p+q=k(2p+q)
Step 6: Isolate k
Dividing both sides by 2p+q (assuming 2p+q=0):
k=31
Question 3:
16x2−(8r+4s)x+rs=0
In the given equation, r and s are positive constants. Find the value of k.
Answer:
The value of k is 1/4.
Explanation:
Step 1: Identify the Equation Type
The given equation is a quadratic equation:
16x2−(8r+4s)x+rs=0
For any quadratic equation Ax2+Bx+C=0, the sum of the solutions can be found with −AB.
Step 2: Define A and B
Here, we identify:
- A=16
- B=−(8r+4s)
Step 3: Calculate the Sum of Solutions
Using the sum of solutions formula:
Sum of solutions=−AB=−16−(8r+4s)=168r+4s
Step 4: Simplify the Sum of Solutions
Simplify 168r+4s as follows:
168r+4s=164(2r+s)=42r+s
Thus, the sum of the solutions is 42r+s.
Step 5: Equate and Solve for k
According to the problem, the sum of the solutions is also k(2r+s). Therefore:
42r+s=k(2r+s)
Step 6: Isolate k
Dividing both sides by 2r+s (assuming 2r+s=0):
k=41