2. Решите уравнения: а) 0,4 · (4x − 0,2) = −4,5 − (1,6x − 2,5); б) (x + 0,75) : 2 1/4 = 3 1/9 : 1 3/4.

а) \[0.4(4x-0.2)=-4.5-(1.6x-2.5)\]

\[1.6x-0.08=-4.5-1.6x+2.5\]

\[1.6x-0.08=-2-1.6x\]

\[3.2x=-1.92\]

\[x=-0.6\]

б) \[(x+0.75):2\frac14=3\frac19:1\frac34\]

\[\frac{x+0.75}{\frac94}=\frac{28}{9}:\frac74=\frac{28}{9}\cdot\frac47=\frac{16}{9}\]

\[x+0.75=\frac94\cdot\frac{16}{9}=4\]

\[x=4-0.75=3.25\]

Ответ: а) \(x=-0.6\); б) \(x=3.25\).