36-4.5x+36=102-7.5x-60
72-4.5x=42-7.5x
72+3.5x=42
3.5x=-30
x=8.57
Answer: 0.125 mg per half minute
Step-by-step explanation:
15mg per hour can be written as 15mg/h
To find out how many mg of medication are delivered per half minute you can convert from hour to minutes
There are 60 minutes in 1 hour, so you can use the conversion factor (1h/60 min) and multiply the expression by it
15 mg/h (1h/60min) = 0.25 mg/min
But the question is per half minute so you have to multiply and divide the previous expression by 0.5 (To obtain 0.5 min in the denominator, which is half minute)
Then,
(0.25 mg/min ) (0.5/0.5) = 0.125 mg/ 0.5 min (0.125 mg per half minute)
We know, cos A + cos B = 2cos(C+D)/2 × cos(C - D)/2
So,
cos 130 + cos 110 + cos 10
cos 130 + 2cos (110+10)/2 × cos( 110-10)/2
cos 130 + 2cos 60 × cos 50
cos ( 180 - 50 ) + 2cos60 cos 50
We know, cos ( 180 - A ) = -cos A
2cos 60 cos 50 - cos 50
Also, cos 60 = 0.5
2×0.5 cos 50 - cos50
cos 50 - cos 50
0 = RHS.
Hence proved
