What is the solution for the system of equations? What does the solution mean in terms of the situation?

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

Find the value of x for which abcd must be a parallelogram -9-6x x-30

This question awards 100 ! i really don’t want to fail i will also mark you !