From the attached graphic:
e = c*h/wavelength therefore,
wavelength = c*h / e
wavelength = 299,792,458 * 6.62606957e-34 / 3.38x10^-19
wavelength = 5.8771e-7 meters
Measurement of angle DEF would equal 180 because 71 plus 109 is 180
Since my answer was deleted here it is:
The variable x represents the cost per pound of meat.
The variable y represents the cost per pound of cheese.
The deli charges $4.50 for a pound of meat.
Have a great day! (this is late but for anyone else who needs it)
Switch y=2x+7 to 2x-y=-7 then multiply that equation by 2 to cancel out the y's. that ends up as 4x-2y=-14 which then you get x=-24. then you substitute x into one of the original equations y= 2(-24)+7 which equals y=-41
