Answer: x=9 is an extraneous solution
Step-by-step explanation:
Given
Function is
for function to exist
Therefore, 9 satisfies the above equation. It is it's extraneous solution.
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1.) 3.5% * 500 = 17.5
2.) 70.0% * 50 = 35.0
3.) 25.0% * 440 = 110.0
4.) 10.0% * 46 = 4.6
Ratio 1:3 can be written as 1/3
sale price / original price : 1/3 = x / 81
this is a proportion, so we cross multiply
(3)(x) = (1)(81)
3x = 81
x = 81/3
x = 27 <== sale price
and notice that 1/3 = 27/81...these are equivalent fractions because that is what proportions are, equivalent fractions