Guys I need your HELP ASAPP

The length of a rectangle is x times the square root of 100. the width is one-half y more than three-halves x. given that the area of the rectangle is 125 cm2, which equation could represent the rectangle in terms of x and y? a) 5xy − 15x = 125 b) 5xy + 15x = 125 c) 15x2 − 5xy = 125 d) 15x2 + 5xy = 125

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

We just started the introduction into circles and i have no idea how to do this.