Answer:
8(x-10)
Step-by-step explanation:
When the calculation is repetitive, I like to let a calculator or spreadsheet do it. The value of the given function is
4·20 -10 = 70
Only the expression 8(x-10) = 8(20-10) = 80 has a larger value for x=20.
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Comment on this solution
It is actually fewer keystrokes to copy the numbers into a calculator, but getting a record of results can be difficult.
