Question

Fie functia f:R->R, f(x)=3-4x. Sa se determine solutiile reale ale inecuatiei
f(x)-1$\geq$4x

Answer 1

f(x)-1$\geq$4x 
3-4x-1$\geq$4x
2-4x$\geq$4x
-4x-4x$\geq$-2
-8x$\geq$-2 / •(-1)
8x$\geq$2
=> x$\geq$2/8
=> x $\geq$ 1/4
x ∈ [1/4, +∞)