Answer:
x = 2
Step-by-step explanation:
Probability that the marble comes to rest in the shaded region is equal to the ratio of the shaded area to the total area.
Probability 'P' = [tex]\frac{A'}{A}[/tex]
Area of the shaded region (A')= (x + 1)(x + 2)
Total area of the figure (A) = (2x + 1)(3x + 2)
P = [tex]\frac{(x+1)(x+2)}{(2x+1)(3x+2)}=\frac{3}{10}[/tex]
10(x + 1)(x + 2) = 3(2x + 1)(3x + 2)
10(x² + 3x + 2) = 3(6x² + 7x + 2)
10x² + 30x + 20 = 18x² + 21x + 6
(18x² - 10x²) + (21x - 30x) + (6 - 20) = 0
8x² - 9x - 14 = 0
x = [tex]\frac{9\pm\sqrt{(-9)^2-4(8)(-14)} }{2(8)}[/tex]
x = [tex]\frac{9\pm \sqrt{81+448}}{16}[/tex]
x = [tex]\frac{9\pm 23}{16}[/tex]
x = -[tex]\frac{7}{8}, 2[/tex]
Therefore, positive value of x = 2 will be the answer.