Question

The length of a rectangle is 3 ft more than twice the width, and the area of the rectangle is 77 ft2 . find the dimensions of the rectangle.

Answer 1

hello : 
let : y  the   length  and : x  the width
y = 2x +3.....(1)
xy = 77 .....(2)
by (1) subsct : y    i n (2) 
x(2x+3) = 77
2x²+3x -77 = 0
the descrimnent : b²-4ac    ... a =2   b= 3    c = -77
3²-4(2)(-77) = 625 = 25²
x1 = (-3-25)/4   negatif refused
x2 = (-3+25)/4 =22/4 = 11/2
x= 5.5
 y = 2(5.5) +3 =14