1. Given the equations $x = 8$ and $y = 11$, what new equation results from adding them? $x+y = $ ___.
2. You are given two equations: $a+b=15$ and $b=9$. By subtracting the second equation from the first, find the value of $a$. $a = $ ___.
3. If you are given the equations $p=4$ and $q=7$, which equation results from multiplying them?
4. You have two equations: $m=10$ and $m-n=3$. By subtracting the second equation from the first, what is the value of $n$? $n = $ ___.
5. If $a=b$ and $c=d$ are true equations, which of the following statements is NOT always a valid new equation based on the property of operating with equations?
6. Solve for $m$ in the equation $\frac{m}{12} = \frac{4}{6}$. The value of $m$ is ___.
7. Use cross-multiplication to solve for $k$ in the equation $\frac{8}{k} = \frac{2}{5}$. The value of $k$ is ___.
8. What is the value of $x$ in the equation $\frac{3.5}{x} = \frac{7}{2}$?
9. Which equation is the correct result of cross-multiplying to solve $\frac{a}{5} = \frac{9}{3}$?
10. Solve for $p$ using cross-multiplication: $\frac{15}{4} = \frac{p}{8}$. The value of $p$ is ___.