To solve the equation 6x 2 - 21 = -5 using the quadratic formula, we need to rearrange the equation to the form ax 2 + bx + c = 0.
First, add 5 to both sides of the equation to eliminate the constant term on the right side:
6x^2 - 21 + 5 = -5 + 5
6x^2 - 16 = 0
Now, the equation is in the form ax 2 + bx + c = 0, where a = 6, b = 0, and c=-16.
Next, we can use the quadratic formula to find the solutions for x:
× = (-0 ‡ v(^2- 4ac))/(2a)
Substituting the values, we have:
x=10土¥10^2-4*6*-16）/（2*6）
×=（=V（O +384））/12
X= （H V384）/12
X= （ V（16*24））/12
x= (‡ V16 * 124) / 12
x= (‡ 4 * V24) /12
x= (1 2* V6)/3
So, the two possible values of x, written as fractions in their simplest form, are: x= 2v6/3
x= -2v6/3
Therefore, the solutions to the equation 6x^2 - 21 = -5 using the quadratic formula are 2v6 / 3 and - 2v6 / 3.