Today, Isaac needs to walk his dog, water the garden, and feed his fish. DDD is the number of minutes it takes to walk his dog, GGG is the number of minutes it takes to water the garden, and FFF is the number of minutes it takes to feed his fish.
The expression G+(D+F)G+(D+F)G, plus, left parenthesis, D, plus, F, right parenthesis describes the total number of minutes it takes Isaac to do all three tasks. We can also use the expression (G+D)+F(G+D)+Fleft parenthesis, G, plus, D, right parenthesis, plus, F to represent the same quantity.
Match each amount in the situation with the expression that represents it.
For reference:
The dog is an animal, and he needs to go outside to walk.
The garden is a bunch of plants (not an animal), and it is outside.
The fish is an animal, and she lives in a water tank inside.
Situation
Expression
THIS IS FOR KHAN ACADEMY

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

c and d is your answers.

stay frosty!

answer: john is 20, mary is 15

step-by-step explanation: