Find the circumference of circle if the area is 300 square centimeters

Area of circle
πr² = 300 cm²
r = √(300/π)
r = 9.77205 cm
r ≈ 9.77cm (3s.f.)

Circumference of circle
= 2πr
= 2π(9.77205)
= 61.39960
≈ 61.4 cm (3s.f.)

1.) Let's simplify the upper polynomial ourselves

8x² - 8x + 2 - 5 + x = 0

We leave 8x² alone because that's the only x² in the polynomial
We add x to -8x getting  -7x
We add 2 to -5 getting -3

Now we have

8x² - 7x -3 = 0

2.) Now we can look at 8x² - gx  -h = 0 and clearly see what numbers should be there
g = 7
h = 3

BE CAREFUL: Don't put g= -7 and h = -3 because then you are getting

8x² - (-7)x -(-3) = 0 which is the wrong polyinomial.