Question

Use the quadratic formula to solve x2 – 3x - 2 = 0.

Answer 1

2.5 or 3.5

Explanation:

The quadratic formula is
`x = -b +/- (√(b^2 + 4ac))/(2a)` .

a, b, and c are determined by the terms in the formula ax^2 + bx + c

They gave you the equation x^2 - 3x - 2, which fits that formula. a is 1, b is -3, and c is -2. So plug those values into the equation:

`x = -(-3) +/- (√((-3)^2 + 4(1)(-2)))/(2(1))`

`x = 3 +/- (√(9 -8))/(2)`

`x = 3 +/- (√(1))/(2)`

`x = 3 +/- (1)/(2)`

So x is 3 plus or minus -1/2. 3 plus -1/2 is 2.5

3 minus -1/2 is 3.5

So the 2 possible x values are 2.5 and 3.5.