How do you balance the equation in number one?

NaNO3 + ___PbO --> ___Pb(NO3)2 + ___Na[2]O

To balace the eqaution, you need to have the same number of atoms for each element on both the reactant (left) and product (right) side. 

To start off, you wanna know the number of atoms in each element on both sides, so take it apart:

[reactants]        [product]
Na- 1               Na- 2

N- 1               N- 2(it's 2 because the the subscript [2] is outside of the parenthesis)

O- 4              O- 7 (same reason as above) 

Pb- 1            Pb- 1 

Na is not balanced out, so add a coefficient to make it the same on both sides.In this case, multiply by 2: 

2NaNO3

Now Na is balanced, but the N and O are also effected by this, so they also have to be multiplied by 2 and they become: 

Na- 2             Na- 2 

N- 2              N- 2 (it balanced out) 

O- 7 (coefficient times subscript, plus lone O)  O- 7 (balanced out) 

Pb was already balanced so no need to mess with it, just put a 1 where needed (it doesn't change anything). 

Now to put it back together, it will look like this: 

2NaNO3 + 1PbO --> 1Pb(NO3)2 + 1Na[2]O