This is how graph gonna look like
Slop 2/1----->>>up 2 right 1
Y intercept ------1 beginning point
Y< so Shade below
Okay so 300 meters per minute and he ran 8 minutes..
300x8=2400
He still had 600 left to go...
2400+600=3,000
He had to run three times longer than Eric...
3000/3=1000
Does that make sense?
(I)
firstly , we will find maximum and minimum y-value
we can see that
maximum value is 5
minimum value is -5
so, we can find amplitude
..........Answer
(II)
we know that
wave length is the length of one wave
we can see that from B to F , there is one wave
and we are given it's length as 20cm
so, wavelength is 20cm......Answer
(III)
we know that
we are given
frequency =100hz
wavelength =20cm
now, we can find velocity
............Answer
The equation is not setup properly, possibly it is your teacher's fault.
From external research, I would say the answer is x = -12.