If you're taking trig, the "sum and difference formulas for trig functions" are basic facts that you'll need to learn and commit to memory. I'd suggest you look up these formulas on the net. You will likely immediately find listings for the sine, cosine and tangent.
I'm just estimating here,
5/48,3/16,0.5,0.75
For this case we have a function of the form:

Where,
A: initial amount
b: decrease rate
x: time in days
Substituting values we have:

Therefore, the graph of the function is a decreasing exponential function in the first quadrant and that has an initial value of 40.
Answer:
graph of exponential function going from left to right in quadrant 1 through the point 0, 40 and approaching the x axis
Answer: 4500 grams
Step-by-step explanation: 1 kilogram is 1,000 grams, so 4 kilograms is 4,000 grams, and half a kilogram is 500 grams. So, 4000 + 500 = 4,500

Subtract 50 from both sides:


hope this helps!