Question

What are the roots of the equation X squared plus 6X -9 equals zero?

Answer 1

Answer: try using desmos.com

Step-by-step explanation:

Answer 2

Answer:

x = -3 + 2√3 and

x = -3 - 2√3)

Step-by-step explanation:

x² + 6x - 9 = 0 can be solved in a variety of ways.  Here I'll "complete the square" to solve for x:

x² + 6x - 9 = 0 can be re-written as x² + 6x  + 9 - 9 - 9 = 0.  To do this, we identify the coefficient of x (which is 6), halve it (obtaining 3), square the result (obtaining 9), and then add and then subtract this result (9) between 6x - 9.  

Simplifying  x² + 6x  + 9 - 9 - 9 = 0  results in:

(x + 3)²                =              18

Taking the square root of both sides, we get:

x + 3 = ±√18)  =  ±3√2

Solving this for the two roots, we get:

x = -3 + 2√3 and

x = -3 - 2√3)