Question 625925: 7x^3-33x=30x
Answer by lenny460(1073)   (Show Source):
You can put this solution on YOUR website! 7x^3 - 33x = 30x
Subtract 30x from each side of the equation.
7x^3 - 33x - 30x = 30x - 30x
Combine like terms:
-33x - 30x = -63x
30x - 30x = 0
We now have:
7x^3 - 63 = 0
Factor out the Greatest Common Factor (GCF) = 7x
7x(x^2 - 9) = 0
Factor a difference between two squares.
7x(x + 3)(x - 3) = 0
Ignore the factor 7.
Subproblem 1
Set the factor x equal to zero (0) and attempt to solve:
x = 0
Subproblem 2
Set the factor (x + 3) equal to zero (0) and attempt to solve.
x + 3 = 0
Subtract 3 from each side of the equation.
x + 3 - 3 = 0 - 3
Combine like terms:
3 - 3 = 0
0 - 3 = -3
x = -3
Subproblem 3
Set the factor (x - 3) equal to zero (0) and attempt to solve:
x - 3 = 0
Add 3 to each side of the equation.
x - 3 + 3 = 0 + 3
Combine like terms:
-3 + 3 = 0
0 + 3 = 3
x = 3
Solution:
x (0, -3, 3)
obuong3@aol.com
|
|
|
