Find all real numbers x such that
(3^x - 27)^3 + (27x - 3)^3 = (3x + 27x - 30)^3
Find all real numbers x such that
(3x−27)3+(27x−3)3=(3x+27x−30)3
well, this is going to be a pain to expand, but i see no other way... Oh god.
Okay after 30 minutes of backbending expanding, i got this:
27x−92+x+3x+7−19683+19683x3−6561x2+729x−27=27000x3−81000x2+81000x−27000
yeah.... thats, quite a bit of math. Now lets simplify! YAY! *sigh..*
27x−92+x+3x+7−7317x3+74439x2+80271x=0
Im acually having fun doing this! No sarcasm like acually!
Okay lets acually do it another way.
[(3x−27+27x−3)][(3x−27)2−(3x−27)(27x−3)+(27x−3)2]=27000x3−81000x2+81000x−27000
(30x−30)[(3(x−9))2−(3(x−9)∗3(9x−1))+(3(9x−1))2]=thethingidon′twannawrite
(30x−30)[9(x2−18x+81)−(9(9x2−82x+9))+(9(81x2−18x+1))=againidon′twannawriteit
9(30x−30)[x2−18x+81−9x2+82x−9+81x2−18x+1]=yeahyeahyeah
270(x−1)[73x2+46x+73]=ohgod
the discriminant of [73x2+46x+73]is negative, so it has no real roots, just saying, you know.
so basically 270(x−1)=(30x−30)3
more simplifying....
270(x−1)=270(100x3−300x2+300x−100)
x−1=100x3−300x2+300x−100
100x3−300x2+299x−99=0
i think ill let you take it from here
Note: I've spent more than an hour on this prob, but i haven't solved it yet, anybody that can give the solution i will appreciate it