I think three might be the correct answer
Standard form means, move the variables to the left-hand-side and leave the constant all by herself on the right-hand-side, usually sorting the variables, so"x" goes first.
now, there's a denominator, we can do away with it, by simply multiplying both sides by the denominator, so let's do so,
Let the numbers be 7x and 4x
According to question
7x-4x =57
3x =57
X=57/3
X=19
So the numbers are
7x=7*19=133
4x=4*19=76
58% is the answer. 7 dividing 12= 0.5833333
you much move the decimal over two places and you would get 58%