How do you solve this?

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

The distance of a chord from the centre of a circle is 12cm and the lenght of the chord is 10cm. find the radius of the circle

Find the difference in area between the circle and the triangle. click on the answer until the correct answer is showing.possible answers: a = 4 pi - 8a = 9 pi - 9/2 √3a = 16/3 pia = 16a = 27 pi