Her phrasing suggests that she would sell numerous water bottles and just a single iced tea. The accurate equation should be 1.25x + 1.49y = 100, as she may offer varying quantities of both.
The options you provided are unclear to me, so I will respond in general terms: to determine if a point (ordered pair) lies on a line, you need to substitute the x-value from that pair into the line's equation and check if the resulting y-value matches the y-value of the ordered pair. For example, if your line is y = 4/3x + 1/3, we can check if (0, 0) and (2, 3) fit this line. We find that y = 4/3·0 + 1/3 gives us 1/3, which does not equal 0, indicating (0, 0) is not on the line. For (2, 3), substituting yields y = 4/3·2 + 1/3 = 3, meaning (2, 3) is on the line.
-keeping a thorough record of the steps and outcomes of a scientific experiment; -conducting an experiment to examine the impacts of gravity on Earth; -solving an expression in stages by adhering to the order of operations.