How Are Expressions Formed?

Get the algebraic expression in the following case using variables, constants and arithmetic operations.

Sum of numbers $a$ and $b$ subtracted from their product. 

If the algebraic expression for the statement, Product of numbers $y$ and $z$ subtracted from $10$ is $10-k$, then write the value of $k$.

Get the algebraic expression in the following case using variables, constants and arithmetic operations:

Number $5$ added to three times the product of numbers $m$ and $n$.

If the algebraic expression for the statement, Numbers $x$ and $y$ both squared and added is $x^k+y^k$, then write the value of $k$.

Get the algebraic expression in the following case using variables, constants and arithmetic operations.

One-fourth of the product of numbers $p$ and $q.$

If the algebraic expression for the statement, the number $z$ multiplied by itself is of the form $z^k$, then find the value of $k$.

One-half of the sum of numbers $x$ and $y$ is the same as $\frac{x+y}{k}$. Write the value of $k$. 

Get the algebraic expression in the following case using variables, constants and arithmetic operations.
Subtraction of $z$ from $y.$