Find the sum of x2 + 3x and -2x2 + 9x +5.

This is the answer

Step-by-step explanation:

Solving    3x2-9x-5 = 0 by the Quadratic Formula .

According to the Quadratic Formula,  x  , the solution for   Ax2+Bx+C  = 0  , where  A, B  and  C  are numbers, often called coefficients, is given by :

           - B  ±  √ B2-4AC

 x =   ————————

                     2A

 In our case,  A   =     3

                     B   =    -9

                     C   =   -5

Accordingly,  B2  -  4AC   =

                    81 - (-60) =

                    141

Applying the quadratic formula :

              9 ± √ 141

  x  =    —————

                   6

 √ 141   , rounded to 4 decimal digits, is  11.8743

So now we are looking at:

          x  =  ( 9 ±  11.874 ) / 6

Two real solutions:

x =(9+√141)/6=3/2+1/6√ 141 = 3.479

or:

x =(9-√141)/6=3/2-1/6√ 141 = -0.479

Two solutions were found :

x =(9-√141)/6=3/2-1/6√ 141 = -0.479

x =(9+√141)/6=3/2+1/6√ 141 = 3.479

15 units use socratic

step-by-step explanation: 15 units