The answer is 175%. We're asked what percentage of x is (2x-y). Since x/y = 4, we can say y = x/4. Then 2x - y = 2x - x/4 = (8x - x)/4 = 7x/4 = 1.75x. To find what percentage of x this is: (1.75x / x) × 100 = 175%. The expression (2x-y) equals 175% of x.