So discriminant gives us 3 possibilites connected with result of the equation b^2-4ac. If it is bigger than zero, there are 2 solutions, if answer is exactly 0, then there is one answer and if the number is lower than 0, there are no solutions.
Discriminant of your quadratic equation is (-4)^2-4*1*5=16-20=-4, so there are no solutions.
Answer:
Step-by-step explanation:
The formula for this is
∠G = 1/2(arcEH - arcHF)
We have angle G (5x - 10) and we have arcEH (195) so we have to solve for x to find the measure of arcEHF so we can add arcEH + arcHF = arcEHF
Filling in the formula with what we have:

which simplifies down a bit to
which simplifies down a bit more to
Multiply both sides by 2 to get rid of the fraction and get:
2(5x - 10) = 178 - 8x which of course simplifies to
10x - 20 = 178 - 8x. Now add 8x to both sides and at the same time add 20 to both sides to get:
18x = 198 so
x = 11. Now we can find the measure of arcHF:
arcHF is 8x + 17, so arcHF is 8(11) + 17 which is 105°.
arcEH + arcHF = arcEHF so
195 + 105 = arcEHF so
arcEHF = 300°
We know that
<span>The nine radii of a regular Nonagon divides into 9 congruent isosceles triangles
</span>therefore
[the area of <span>a regular nonagon]=9*[area of isosceles triangle]
</span>[area of isosceles triangle]=b*h/2------> 15*20.6/2----> 154.5 cm²
so
[the area of a regular nonagon]=9*[154.5]------> 1390.5 cm²
the answer is
1390.5 cm²