The mistake is that they subtracted 21 instead of adding it. you would have had to added 21 to the left side to cancel it out and added 21 to the right side to get p= 55
You can use Socratic for aleks it really helps :)
4.3 Solving 3x2-2x-1 = 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 = 3
B = -2
C = -1
Accordingly, B2 - 4AC =
4 - (-12) =
16
Applying the quadratic formula :
2 ± √ 16
x = —————
6
Two real solutions:
x =(2+√16)/6
or:
x =(2-√16)/6
Answer:
The correct answer for the value of x here is 3.6
Step-by-step explanation:
In order to find this, follow the order of operations.
-(-2 - 5x) + (-2) = 18 ----> Distribute the -
2 + 5x - 2 = 18 ----> Add like terms
5x = 18 -----> Divide by 5
x = 3.6
The answer to this is #1 10
