No mathematics the most common way of solving an equation will be PEMDAS so the answer for your question will most likely be subtraction.
In warmer weather gases tend to expand and take up more room, thus increasing pressure. but in colder weather they will condense or contract and take up less space, therefore lowering the pressure of the tire in this situation.
Answer:

Explanation:
Your unbalanced nuclear equation is:

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.
Then
84 = x + 2, so x = 84 - 2 = 82
210 = y + 4, so y = 210 - 4 = 206
Element 82 is lead, so the nuclear equation becomes

Answer:
0.225 mol = 0.23 mol to 2 significant figures
Explanation:
Calculate the moles of oxygen needed to produce 0.090 mol of water
The equation of the reaction is given as;
2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O
From the equation of the reaction;
5 mol of O2 produces 2 mol of H2O
x mol of O2 produces 0.090 mol of H2O
5 = 2
x = 0.090
x = 0.090 * 5 / 2
x = 0.225 mol