Number Systems

Reduce the fractions $$\dfrac{348}{319},\ \dfrac{221}{247},\ \dfrac{437}{551}$$ to the lowest terms.
Arrange the following decimals in ascending order.
$$2.165, 2.018, 2.2, 2.61$$
$$4.03, 4.30, 4.308, 4.380$$
Evaluate $$19 \div (31)$$  = 
Find the difference between $$3.25$$ and $$9.86$$
If $$x =2\sqrt{3} + 2\sqrt{2}$$, find :