Question

WEDNESDAY: Use the quadratic formula to solve the following: 3x^2 - 6x-12 = 0*

a. 3.236 or -1.236
b. -3.236 or 1.236
c. 04 or 9
d. 2.487 or -5.859
e. None of these​

Answer 1

a.) 3.236 or -1.236

Explanation:

Used an online calculator for this answer...

Using the Quadratic Formula where

`x = ( -b \pm √(b^2 - 4ac))/( 2a )\\x = ( -(-6) \pm √((-6)^2 - 4(3)(-12)))/( 2(3) )\\x = ( 6 \pm √(36 - -144))/( 6 )\\x = ( 6 \pm √(180))/( 6 )`

The discriminant b^2−4ac > 0

so, there are two real roots.

Simplify the radical...

`x = ( 6 \pm 6√(5)\, )/( 6 )\\x = ( 6 )/( 6 ) \pm (6√(5)\, )/( 6 )\\x = 1 \pm √(5)\,`

This simplifies to...

`x = 3.23607\\x = -1.23607`