90/139 is the only fraction not equivalent to 45/70.
To find if a fractions are equivalent, divide the numerator by the denominator for each fraction.
45/70=0.642857
27/42=0.642857
9/14=0.642857
63/98=0.642857
Notice how all of these get you the same number. However, when you divide 90 by 137, you get 0.64748, which is not the same as the others. Therefore, 90/137 is the fraction that is not equivalent to 45/70.
Answer:
40:16, 16:40, 40/16, 16/40
X = 8/3
I hope this helped!
