Решим уравнения.
a) $$ (4.6x + 5.8) : 1.6 = 6.5 $$
$$ 4.6x + 5.8 = 6.5 * 1.6 $$
$$ 4.6x + 5.8 = 10.4 $$
$$ 4.6x = 10.4 - 5.8 $$
$$ 4.6x = 4.6 $$
$$ x = 1 $$
б) $$ 4.2x + 8.4 = 14.7 $$
$$ 4.2x = 14.7 - 8.4 $$
$$ 4.2x = 6.3 $$
$$ x = rac{6.3}{4.2} $$
$$ x = 1.5 $$
Ответ: а) $$x = 1$$, б) $$x = 1.5$$