2/5x^6+2=27.6
Solve for x:
(2x^6)/5+2 = 27.6
27.6 = 138/5:
(2 x^6)/5+2 = 138/5
Subtract 2 from both sides:
(2 x^6)/5 = 128/5
Multiply both sides by 5/2:
x^6 = 64
Taking 6^th roots gives 2 times the 6^th roots of unity:
Answer: |
| x = -2 or x = 2 or x = -2 (-1)^(1/3) or x = 2 (-1)^(1/3) or x = -2 (-1)^(2/3) or x = 2 (-1)^(2/3)
2/5x^6+2=27.6
Solve for x:
(2x^6)/5+2 = 27.6
27.6 = 138/5:
(2 x^6)/5+2 = 138/5
Subtract 2 from both sides:
(2 x^6)/5 = 128/5
Multiply both sides by 5/2:
x^6 = 64
Taking 6^th roots gives 2 times the 6^th roots of unity:
Answer: |
| x = -2 or x = 2 or x = -2 (-1)^(1/3) or x = 2 (-1)^(1/3) or x = -2 (-1)^(2/3) or x = 2 (-1)^(2/3)
Nice answer, Guest....let me expand upon this, starting here:
x^6 = 64
x^6 - 64 = 0
(x^3 - 8) (x^3 + 8) = 0
(x - 2) ( x^2 + 2x + 4) ( x + 2) ( x^2 - 2x + 4) = 0
We get the two real solutions of x = 2 and x = -2 by setting the first and third factors to 0 and solving
Then
x^2 + 2x + 4 = 0
x^2 + 2x + 1 = -4 + 1
(x + 1)^2 = -3
x + 1 = ( +/-)sqrt(3) i
x = (+/-) sqrt (3) i - 1 produces two non-real solutions
And
x^2 - 2x + 4 = 0
x^2 - 2x + 1 = - 4 + 1
(x - 1)^2 = -3
x - 1 = (+/-)sqrt(3) i
x = (+/-)sqrt(3) i + 1 produces the other two non-real solutions