Question 545158
if y=5/4x, then 



-10x+8y=-6


-10x+8(5/4x)=-6



Notice how i replaced 'y' with '5/4x'. This is possible since 'y' and '5/4x' are the same



From here, solve -10x+8(5/4x)=-6 for x



Once you have a solution for x, use it to find y.