The solution of the quadratic equation using the factoring method and the quadratic formula is; x = 2.5 and x = -3
The steps for the factoring and quadratic formula methods used for solving the quadratic equation can be presented as follows;
The quadratic function can be presented as follows;
2·x² + x - 15 = 0
The above equation can be solved using the factoring method to get;
Factoring the above equation, we get;
2·x² + 6·x - 5·x - 15 = 0
2·x·(x + 3) - 5·(x + 3) = 0
2·x·(x + 3) - 5·(x + 3) = (2·x - 5)·(x + 3)
(2·x - 5)·(x + 3) = 0
Therefore; 2·x - 5 = 0 or x + 3 = 0
x = 5/2 and x = -3
5/2 = 2.5
x = 2.5 and x = -3
The equation 2·x² + x - 15 = 0 can be solved using the quadratic formula as follows;
The quadratic formula for the quadratic equation of the form;
a·x² + b·x + c = 0 is;

Comparing the specified quadratic equation with the equation for the quadratic formula, we get;
x = (-1 ± √(1² - 4 × 2 × (-15)))/(2 × 2)
x = (-1 ± 11))/(4)
x = 10/4 and x = -12/4
x = 2.5 and x = -3