Answer:
Explanation:
Put the value where the variable is and do the arithmetic. It can save some steps to simplify the expression first.
35 -c³ +8 = 43 -c³
c = 1
43 - 1³ = 43 -1 = 42
c = 2
43 - 2³ = 43 -8 = 35
c = 3
43 -3³ = 43 -27 = 16
The values that go in the blanks are 42, 35, 16.
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Additional comment
It does not take long to learn how to use a spreadsheet for evaluating the same formula with a number of different values of the variable(s). Graphing calculators can do this, too. It is always appropriate to use the right tool for the job.
Familiarity with multiplication and addition facts is a very good place to start. It is also useful to memorize the squares and cubes of small integers. The latter are needed here.