AlgebraPlease check
posted by JoniAnne on .
Please check
Solve 3 > sqrt(3x)
3x >=o
x>=o/3
x>=0
square both sides and you have 3x < 3^2
3x,9
x<9/3
x<3
answer is 0<=x<3 correct or not?
3(cube) sqrt(25) = 3
cube both sides = 25x = 27
5x = 25
x = 5, correct?
Thank you

1. Correct.
2. 3^3*sqrt(2  5x) = 3,
27*sqrt(2  5x) = 3,
Divide both sides by 27:
sqrt(2  5x) = 3/27 = 1/9,
Square both sides and get:
2  5x = 1/81,
5x = 1/81  2,
5x = 1/81  162/81,
5x = 161/81,
Multiply both sides by 1/5:
x = (161 / 81) * (1/5) = 161 / 405.
CHECK:
3^3*sqrt(2  (5*161/405)) =
27*sqrt(2  1.9877) =
27*sqrt(0.01235) =
27 * 0.11111 = 3.