Ответы: 1) x = 7.5; 2) x = 1.5; 3) x = 4.6; 4) x = 3.36; 5) y = 6.58; 6) y = 4.3
\[3\frac{1}{5}x + 2.9x = 36.6\]
\[3.2x + 2.9x = 36.6\]
\[6.1x = 36.6\]
\[x = \frac{36.6}{6.1}\]
\[x = 6\]
\[5.6x - 2.4x = 4.8\]
\[3.2x = 4.8\]
\[x = \frac{4.8}{3.2}\]
\[x = 1.5\]
\[9x - 7\frac{9}{20}x = 4.03\]
\[9x - 7.45x = 4.03\]
\[1.55x = 4.03\]
\[x = \frac{4.03}{1.55}\]
\[x = 2.6\]
\[(x + 2.6) : 0.8 = 7.45\]
\[x + 2.6 = 7.45 \cdot 0.8\]
\[x + 2.6 = 5.96\]
\[x = 5.96 - 2.6\]
\[x = 3.36\]
\[(7.8 - y) : 6.1 = 0.2\]
\[7.8 - y = 0.2 \cdot 6.1\]
\[7.8 - y = 1.22\]
\[y = 7.8 - 1.22\]
\[y = 6.58\]
\[16.5 : (7.6 - y) = 5\]
\[7.6 - y = \frac{16.5}{5}\]
\[7.6 - y = 3.3\]
\[y = 7.6 - 3.3\]
\[y = 4.3\]
Ответы: 1) x = 7.5; 2) x = 1.5; 3) x = 4.6; 4) x = 3.36; 5) y = 6.58; 6) y = 4.3