Question

Giải các bất PT sau

a. \(7x-5\ge-3x+13\)

b. \(9x^2+4x-3\ge\left(3x+2\right)^2\)

c. \(\frac{3x-5}{8}+\frac{1-5x}{4}< \frac{1}{2}\)

Answer 1

a,<=>7x+3x≥13+5

<=>10x≥18

<=>x≥\(\frac{9}{5}\)

b,<=>9x²+4x-3≥9x²+12x+4

<=>(9x²+4x-3)-(9x²+12x+4)≥0

<=>-8x-7≥0

<=>-8x≥7

<=>x≤\(\frac{-7}{8}\)

c,<=>\(\frac{3x-5}{8}\)+\(\frac{2-10x}{8}\)<\(\frac{4}{8}\)

<=>3x-5+2-10x<4

<=>-7x-3<4

<=>-7x<7

<=>x>-1