If it took 8 hours to clean 12 houses, how many houses could be cleaned in 12 hours

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

Atextile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms. the company wishes to test the hypothesis upper h subscript 0 baseline colon mu equals 12 against upper h subscript 1 baseline colon mu less-than 12 using a random sample of n equals 4 specimens. calculate the p-value if the observed statistic is x overbar equals 11.8. round your final answer to five decimal places (e.g. 98.76543).