x^3/27 - 3x^2 + 81x -729 = 25+30+9
multiply everything by 27 to clear the fraction
x^3 - 81x^2+2187x - 19683 = 1728
subtract by 1728
x^3 - 81x^2 + 2187x - 21411=0
x^3 - 8x^2 + 2187x -21411 = (x-39)(x^2-42x+549)
since two of the solutions are complex/imaginary numbers, the only solution is 39.
1) If x/2, x/3, and x/6 are angle measures of a triangle, they must add up to 180.
x/2 + x/3 + x/6 = 180
Find the common denominator:
3x/6+2x/6 + x/6 = 180
Multiply both sides by 6:
x = 180
x/6, the smallest angle, is 30.
2) Correct me if I'm wrong, but isn't it just 135?
3) 108/120 = 9/10