Solution for Problem 1.3.1

Solve for x:   x2 + 5x + 3 = 0    Quadratic Formula

ax2 + bx + c = 0

Solve

Step

a = 1, b = 5, c = 3

Identify coefficients

Substitute values for a, b , and c.  Then simplify.
There are 2 distinct answers.

Approximations...
x » (-5 + 3.60555)/ 2 = -0.69723
 x » (-5 – 3.60555)/ 2 = -4.30278

Check 

If x  = -0.69723, then
(-0.69723)2 + 5(-0.69723) + 3 = 0
    0.48613 – 3.48615 + 3 = 0
0.00002 » 0  
**Rounding error

If x  = -4.30278, then 
(-4.30278)2 + 5(-4.30278) + 3 = 0
  18.51392 – 21.5139 + 3 = 0
 0.00002 » 0   
**Rounding error