Question

solve X=2y and y=2x​

Answer 1

Step 1) Because the first equation is already solved for x we can substitute 2y for x in the second equation and solve for y:

y=2x becomes:

y=2⋅2y

y=4y

y−y=4y−y

0=4y−1y

0=(4−1)y

0=3y

03=3y3

0=3y3

0=y

y=0

Step 2) We can now substitute 0 for y in the first equation and calculate x:

x=2y becomes:

x=2⋅0

x=0

Therefore the solution is:

x=0 and y=0

Or

(0,0)

We can also graph these equations showing the solution:

graph{(x-2y)(y-2x) = 0 -5, 5, -2.5, 2.5