Well, no, 2:4 and 5:6 are not equivalent because let’s say if we drew 2:4 and 5:6 as a pizza, then 2:4 is 50% while 5:6 is 83%.
Y=mx+b
m=slope
b=yintercept
slope=-3/4
yintercept=3/2
y=-3/4x+3/2
it could also be written
3x+4y=6
The answer is x-1 hope that helps not sure if it does