a rectangle has sides of length (2x+3)cm and (x+1)cm. what is the domain of x if the area of the rectangle is greater or equal to 10cm^2

(2x+3)(x+1) >= 10

2x^2 + 5x - 7 >= 0
(2x+7)(x-1) >= 0
since the parabola opens upward, y < 0 between the roots. So, the domain is
x <= -7/2 OR x >= 1