\begin{array}{rl}
5 x - 5 y & = -4\
20 x - 20 y & = -16
\end{array}

Question

\begin{array}{rl}
5 x  - 5 y & = -4\
20 x  - 20 y & = -16
\end{array}

anonymous · Answer

sulmitaneous equation?

anonymous · Answer

the question said solve the following system of equations

anonymous · Answer

if yes
for equation (1) express x in terms of y
x=(-4+5y)/5 plug it in equation (2)
and solve for y
when u find y, plug it in equation (1) to find x

anonymous · Answer

i got x is 1 and y is 9/5

hartnn · Answer

how?
actually, try this
multiply 1st equation throughout by 4
what do u get ?

anonymous · Answer

i get x=-.8

hartnn · Answer

5x−5y=−4
multiplying 4 throughout

20x-20y = -16
this is same as your second equation
so if you subtract these, you get 
0=0
which is always true for any value of x or y
which means there are infinite values of x and y that satisfy your original system of equations