Liam has 9/10 gallon of paint for painting the birdhouses he sells at the craft fair. each birdhouse requires 1/20 gallon of paint. how many birdhouses can liam paint? show your work.

The number of birdhouses is:
(9/10) : (1/20) = (9/1) * (20/10) = 9 * 2 = 18

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

The correct answer is -20y