The total number of gallons of water in a tank, w, after t minutes is given in the table and the graph below. What is an equation showing the relationship between w and t? A. w = 2t B. w = 2 + t C. w = 4t D. w = 4 + t
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Answer:
C. w = 4t
Step-by-step explanation:
Let's examine the way t and w are related to each other, one point at a time starting with (0, 0). This point really doesn't tell us much, but we do know that this relationship must be proportional since any line that goes through the origin (the point (0, 0)) is proportional. we can rule out B. 2 + t and D. 4 + t since neither of these go through the origin. 2 + t goes through the point (0, 2) and 4 + t goes through the point (0, 4).
Now, we have two options left: A. w = 2t and C. w = 4t. Which one is correct? Well, let's look at the point (1, 4). 1 × 2 is not equal to 4, but 1 × 4 is equal to 4, so C. w = 4t must be the correct option.
We can test this on the rest of the points as well: 2 × 4 = 8 and 3 × 4 = 12. Hopefully that's helpful! If you have questions or need clarification on anything, let me know. :)