PLZ help 2.10 unit test

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.