-2x + 55 I think is the right answer ( is that the format you were looking for )
Answer:
y=1
Step-by-step explanation:
thats the answer
We notice there are 4B and 4G (shown in the photo)
P(picking 1st a Green) = 4/8 (having picked a green -and not replacing it- the remaining number of marbles is 3G + 4B)
P(picking 2nd a Green) =3/7
P(picking 1st green AND picking 2nd Green )=(4/8) x (3/7) = 12/56≈ 0.21=21%
we can use pythagorean identieis
remember that 
also remember that
and 
so if we take
and divide both sides by
we get



subtracting
from both sides

now subsitute into original problem



the answer is -1