A lab assistant needs to create a \( 350 mL \) mixture that is \( 3.5 \% \) hydrochloric acid. The assistant has solutions of \( 2 \% \) and \( 4.5 \% \) in supply at the lab. Using the variables \( x \) an \( y \) to represent the number of milliliters of the \( 2 \% \) solution and the number of milliliter of the \( 4.5 \% \) solution respectively, determine a system of equation that describes the situation.
Enter the equations below separated by a comma.
How many milliliters of the \( 2 \% \) solution should be used?
x=
How many milliliters of the \( 4.5 \% \) solution should be used?
\( y = \)