SOLUTION: what number is used to complete the sqaure for the equation x^2=20x a.)-100 b.)-10 c.)10 d.)100

Algebra.Com
Question 325626: what number is used to complete the sqaure for the equation x^2=20x
a.)-100
b.)-10
c.)10
d.)100
Found 2 solutions by AAfter Search, JBarnum:
Answer by AAfter Search(61)   (Show Source): You can put this solution on YOUR website!
x^2=20x
=> x^2 - 20x = 0
To make the quadratic equation a complete square, the determinant should be zero.
Hence, if the required equation is x^2 - 20x +c = 0
Determinant = (-20)^2 - 4 x 1 x c = 0
=> 400 = 4c
=> c = 400/4 = 100.
Answer: d
Answer by JBarnum(2146)   (Show Source): You can put this solution on YOUR website!
+100


Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=0 is zero! That means that there is only one solution: .
Expression can be factored:

Again, the answer is: 10, 10. Here's your graph:
RELATED QUESTIONS

whta number is used to complete the squrare for the equation x^2-12=0 a.36 b.-36... (answered by checkley77)
What number is used to complete the square for the equation y^2 + 16 = -y? a) -64... (answered by ankor@dixie-net.com)
what number is used to complete the square for the equation r^2-3r=4 a.)-2.25... (answered by Fombitz)
Write the quadratic function in the vertex form. y = x2 - 20x A. y = (x + 20) 2 -... (answered by rapaljer)
Solve the inequality 100-x^2>=0 Answer choices: A.) x<=-50 or x>= 50 B.) x<=10 C.) (answered by chiexpert)
A company noticed a linear relationship between the price of a luggage set and the number (answered by Fombitz)
If 100-2xy-y^2=x^2, which of the following must be true? a. x-y=10 b. x^2+y^2=100 c.... (answered by richard1234,mananth)
the question is: solve the quadratic equation by completing the square: x^2-20x=0 (answered by solver91311,RAY100,Edwin McCravy)
What is the value of 2 – 4 + 6 – 8 + 10 – 12 + 14 ………. – 100 ? (A) -50 (B) 0 (C) 50... (answered by richwmiller)