Question 982010


You have a linear system of two equations in two unknowns


{{{system(4x-y=5, 
4x+4y=-4)}}}.


Subtract the second equation from the first one.  You will get a single equation in one unknown


-y - 4y = 5 - (-4),   or


-5y = 5 + 4,   or


5y = -9.


Hence,  y = {{{-9/5}}} = -1.8.


Now, &nbsp;substitute this value of &nbsp;<B>y</B>&nbsp; into the first equation of the original system. &nbsp;You will have 


4x - (-1.8) = 5, 


4x = 5 - 1.8,


4x = 3.2,


x = {{{3.2/4}}} = 0.8.


<B>Answer</B>. &nbsp;x = 0.8, y = -1.8.