Answer:
8d+12-6d+10
2d+22
Step-by-step explanation:
I think the way that you do is 5/5+3=5/8
5/8*4=2.5 so 2.5 is the answer
Hi there!
We can use the following equation:

z = amount of standard deviations away a value is from the mean (z-score)
σ = standard deviation
x = value
μ = mean
Plug in the knowns for both and rearrange to solve for the mean:

Other given:

Set both equal to each other and solve:

B is correct since there is one output for every input !!
have a great day :))