Final answer:
The given questions involve finding the values of variables using equations. We can use techniques such as substitution or elimination to solve these types of problems.
Step-by-step explanation:
The given question involves the use of variables and equations to find the values of the variables. In the first question, we are given two equations with three variables and we are asked to find the value of one of the variables.
Similarly, in the second question, we are given three equations with three variables and we need to solve for another variable.
To solve these types of problems, we can use techniques such as substitution or elimination to find the values of the variables. By substituting one equation into another or by eliminating one variable at a time, we can solve for the remaining variables.
For example, in the first question, we can substitute the value of ST into the equation RS = 3y + 1 and solve for y. Similarly, in the second question, we can use elimination to solve for y.