Question

[x] denotes the greatest integer value just below x and {x} its fractional value . the sum of [x]^3 and {x}^2 is -7.91.find x.

Answer 1

[x]^3 = ( x-{x} )^3
( x-{x} )^3 + {x}^2 =-7.91

Answer 2

take it to mean that "{x} its fractional value" is the fractional part, like \(\{2.15\}=.15\)