Just rearrange the inequalities to make x the subject.
2 + y <= 3
Subtract 2 from both sides.
y <= 1
7x > 56
Divide both sides by 7.
x > 8
Well I don't know where inequalities would come in but the third length would be solved as follows.
a^2+b^2=c^2
10^2+18^2=424

Answer;

I hope this is correct, its what I would do if I had this equation.
6.5 - 3 = 3.5
11 - 6.5 = 4.5
16.5 - 11 = 5.5
23 - 16.5 = 6.5
From this, you can see that the number being added is increasing by 1 each time.
Therefore, the pattern is adding 3.5, then 4.5, then 5.5, then 6.5, and so on.