Question

Tìm x biết:

a) 2x-3 > 5x-4

b) -5x+6 < 1/3

c) 7-8x > 9/16

Answer 1

\(2x-3>5x-4\)

\(\Leftrightarrow2x-5x>-4+3\)

\(\Leftrightarrow-3x>-1\)

\(\Leftrightarrow x>\frac{1}{3}\)

Answer 2

\(-5x+6< \frac{1}{3}\)

\(\Leftrightarrow-5x< \frac{1}{3}-6\)

\(\Leftrightarrow-5x< \frac{1}{3}-\frac{18}{3}\)

\(\Leftrightarrow-5x< \frac{-17}{3}\)

\(\Leftrightarrow x< \frac{-17}{3}\div\left(-5\right)\)

\(\Leftrightarrow x< \frac{17}{15}\)

Answer 3

\(7-8x>\frac{9}{16}\)

\(\Leftrightarrow8x>7-\frac{9}{16}\)

\(\Leftrightarrow8x>\frac{112}{16}-\frac{9}{16}\)

\(\Leftrightarrow8x>\frac{103}{16}\)

\(\Leftrightarrow x>\frac{103}{16}\div8\)

\(\Leftrightarrow x>\frac{103}{124}\)