A root of x^2-5x-1=0 is?

Question

Please help me! I don't understand this question, and I have a test tomorrow:(!

Answer 1

 x²-5x-1=0

 

Quadratic equation is for format:  ax²+bx+c=0

For this equation  a = 1, b = -5, c = -1

 

Plugging into  x = (-b ± √(b² - 4ac)) / 2a

 

Your two roots are derived from 

x= [-(-5)±√((-5)²-4(1)(-1))]/2(1)

 

This is just plugging into the formula.  Distribute through

your signs .. such as -(-5)=5 ... and work out the total

under the square root sign and you have your two

roots for the equation given.

Answer 2

The root is the x value that will make the result equal to zero.  I suggest you use the quadratic formula to find the root(s):

 

x = (-b ± √(b² - 4ac)) / 2a