How many solutions are there for the system x^2+4y^2=100 and 4y-x^2=-20

For the equations below which statement is true ?

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

Need 50 will mark brainliest answer. find the lengths of all the sides and the measures of the angles.