Algebra 2ChallengeSystems of Equations

Systems of Equations · Challenge problem

Three equations, only two unknowns. Solve the first two for $x$ and $y$ , then give the value $e$ must take for the third equation to hold as well.

\begin{aligned} x + y = c \\ 2 x - y = d \\ 3 x + 2 y = e \end{aligned}