Question

Use the quadratic formula to solve the equation. x2 + 7x – 4= 0

Answer 1

Answer:

Well.

                      \       /

                2 solutions

           x =(-7-√65)/2=-7.531

          x =(-7+√65)/2= 0.531

                    /           \

Using the quadratic formula..

 2.3     Solving    x2+7x-4 = 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   =     1

                 B   =    7

              C   =   -4

Accordingly,  B2  -  4AC   =

              49 - (-16) =

        65

Applying the quadratic formula :

 -7 ± √ 65

  x  =    —————

         2

√ 65   , rounded to 4 decimal digits, is   8.0623

So now we are looking at:

         x  =  ( -7 ±  8.062 ) / 2

                          \      /

                Two real solutions:

                 x =(-7+√65)/2= 0.531

                       or:

                 x =(-7-√65)/2=-7.531

                          \        /

*eliza*