6.252 Решите уравнение: a) $$4x + 7x = 1,98$$; б) $$9z - 5z = 5,52$$;

a) $$4x + 7x = 1.98$$ $$11x = 1.98$$ $$x = \frac{1.98}{11} = 0.18$$ б) $$9z - 5z = 5.52$$ $$4z = 5.52$$ $$z = \frac{5.52}{4} = 1.38$$ Ответ: a) $$x = 0.18$$, б) $$z = 1.38$$