Question

tim X biet : 28.75 < X : 0.25 + X : 0.5 < 31.6

Answer 1

X la so tu nhien nha

Answer 2

\(28,75< x\div0,25+x\div0,5< 31,6\)

\(\Leftrightarrow28,75< \frac{100x}{25}+\frac{10x}{5}< 31,6\)

\(\Leftrightarrow28,75< \frac{4x}{1}+\frac{2x}{1}< 31,6\)

\(\Leftrightarrow28,75< 4x+2x< 31,6\)

\(\Leftrightarrow28,75< 6x< 31,6\)

\(\Leftrightarrow6.4,791\left(6\right)< 6x< 6.5,2\left(6\right)\)

\(\Leftrightarrow4,791\left(6\right)< x< 5,2\left(6\right)\)

\(\Leftrightarrow x=5\)

Answer 3

20 là mình bấm nhầm