solve it fassssttttt x^2-12x-84
Answers
therefore,
so then keep the values, -12'2 - 4(1)(-84)
= 144 - 336
= -222
since discriminant is (- ve ) therefore it will not have real roots it will have complex roots , and if u wanna further solve it then roots will in form of a+ib
ANSWER:-------------
T he Square Root Principle says that When two things are equal, their square roots are equal.
Note that the square root of
(x+6)2 is
(x+6)2/2 =
(x+6)1 =
x+6
Now, applying the Square Root Principle to Eq. #2.2.1 we get:
x+6 = √ 120
Subtract 6 from both sides to obtain:
x = -6 + √ 120
Since a square root has two values, one positive and the other negative
x2 + 12x - 84 = 0
has two solutions:
x = -6 + √ 120
or
x = -6 - √ 120
Solve Quadratic Equation using the Quadratic Formula 2.3 Solving x2+12x-84 = 0 by the Quadratic Formula .
According to the Quadratic Formula, x , the solution for Ax2+Bx+C = 0 , where A, B and C are numbers, often called coefficients, is given by :
- B ± √ B2-4AC
x = ————————
2A
In our case, A = 1
B = 12
C = -84
Accordingly, B2 - 4AC =
144 - (-336) =
480
Applying the quadratic formula :
-12 ± √ 480
x = ——————
2
Can √ 480 be simplified ?
Yes! The prime factorization of 480 is
2•2•2•2•2•3•5
To be able to remove something from under the radical, there have to be 2 instances of it (because we are taking a square i.e. secondroot).
√ 480 = √ 2•2•2•2•2•3•5 =2•2•√ 30 =
± 4 • √ 30
√ 30 , rounded to 4 decimal digits, is 5.4772
So now we are looking at:
x = ( -12 ± 4 • 5.477 ) / 2
Two real solutions:
x =(-12+√480)/2=-6+2√ 30 = 4.954
or:
x =(-12-√480)/2=-6-2√ 30 = -16.954
hope it helps:---
T!—!ANKS!!!!