4x3+3≤32≤x2+5
Split into two and solve separately
1). 4x3+3≤32
Multiply through by 4x
4x3(4x)+3(4x)≤32(4x)
⟹3+12x≤38x
Multiply through by 3
3(3)+12x(3)≤38x(3)
⟹9+36x≤8x
9−9+36x−8x≤8x−8x−9
⟹28x≤−9⟹x≤28−9
2). 32≤x2+5
Multiply through by 3x
32(3x)≤x2(3x)+5(3x)
⟹2x≤6+15x⟹2x−2x−6≤6−6+15x−24
⟹−6≤13x⟹x≥13−6
Combining the two,we have
13−6≤x≤28−9
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