So we want to know what do we need to measure to determine the wavelength of the wave on the image. A wavelength is the distance between peaks of the wave. More generally, the distance on which the wave shape repeats. So on the image we need to measure X to determine the wavelength. So the correct answer is X.
In the standard form of quadratic

the discriminant is

In your quadratic, a = 1, b = -9 and c = -10
Now you need to plug these values into the expression for the discriminant.
There are 9 seniors.
Although there are several ways of solving this problem, I just did what was easiest for me in my head. I divided 36 by 4, which gave me 9.
Answer:
x = 8
y = 6
Step-by-step explanation:
First and foremost, it's an equilateral triangle, therefore all sides and angles are equal.
Knowing that the sum of angle in a triangle is 180°, therefore each angle is 60°.
Then equating (7x+4)° to 60, we have that,
7x+4=60
7x=60-4
7x=56
x=56÷7
x=8.