Solve the following system of equations with the substitution method:

$\displaystyle {\left\lbrace\begin{array}{ccc} {x}+{y}&=&-{20}\\{y}&=&{4}{x}\end{array}\right.}$

Answer: $\displaystyle {\left({x},{y}\right)}=$ (,)
Preview $\displaystyle {x}$: Preview Question 6 Part 1 of 2  
Preview $\displaystyle {y}$: Preview Question 6 Part 2 of 2  


Enter your answers as integers or as reduced fractions in the form A/B.