What is the solution set of the following system of equations?

5x - 3y - 10 = 0
x + y - 7 = 0

A{(31/8, 25/8)}
B{(25/8, 31/8)}
C{(45/2, 31/2)}
D{(31/2, 45/2)}

Question

What is the solution set of the following system of equations?

5x - 3y - 10 = 0
x + y - 7 = 0

A{(31/8, 25/8)}
B{(25/8, 31/8)}
C{(45/2, 31/2)}
D{(31/2, 45/2)}

anonymous · Answer

i think A is write:
5x-3y-10=0   => y=(5/3)x-10/3
x+y-7=0        => y=-x+7
{y=(5/3)x-10/3
{y=-x+7
multiply second equation in (-1) => (-1)(y=-x+7)
so 
y=(5/3)x-10/3
-y=x-7
add two equation (add left side with left side & rught side with right side) then:
0=(8/3)x-31/3
(8/3)x=31/3
x=31/8
y=-x+7   => (x=31/8)=>y=31/8      =>y=25/8
so : x=31/8  &   y=25/8