Step-by-step explanation:
Hi... Your answer is 3 units
let's bear in mind that
standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient
so, let's do away with the denominators by multiplying both sides by the LCD of all fractions, in this case 6.

10 by 60 Would create a rectangle, so would 20 by 50, so would 30 by 40. These would all create rectangles, but the most like a rectangle would be 10 by 60, or 20 by 50.
10x2=20 60x2=120 120+20=140
20x2=40 50x2=100 100+40=140