The last one
x^2-3X-28
Z Z Z Z Z
Hello!
x² - 4x + 6 = 9 <=>
<=> x² - 4x + 6 - 9 = 0 <=>
<=> x² - 4x - 3 = 0 <=>
<=> x = -(-4)±√(-4)²-4×1×(-3)/2×1 <=>
<=> x = 4±√16+12/2 <=>
<=> x = 4±√28/2 <=>
<=> x = 4±2√7/2 =>
=> x = 4+2√7/2 and x = 4-2√7/2 =>
=> x = 2+√7 and x = 2-√7
The equation has two solutions.
Good luck! :)
Since the area of a circle is π

, and our radius is 9 we know the total area to be 254.469, and the ratio of sector area to total area is 169.56/254.469 = .6663. There are 360 degrees in a circle, so:

≈ 240°
240 degrees