During the period 1994 - 2004, the 'National Income' ,(NI) of Australia grew about 5.2% per year (measured in 2003 U. S, dollars). In 1994 , the NI of Australia was $ 4 billion.
Now,
(2020 - 1994) = 26
Assuming this rate of growth continues, the NI of Australia in the year 2020 (in billion dollars) will be,
These are the same line so all points are the same so that means there are infinite answers.
If ONLY the number in front of the x was the same there would be 0 answers, they would be parallel lines, and if the number in front of the xs were different there would only be one answer.