Based on the chart above, which of the following could express the relationship between x and y ?
A. y = x - 4
B. y = 2x - 1
C. y = 2x + 2
D. y = 3x - 3
Answer:B
Based on the chart above, which of the following could express the relationship between x and y ?
A. y = x - 4 B. y = 2x - 1 C. y = 2x + 2 D. y = 3x - 3
Explanation: B Plug in the values from the chart! Use the pair (-3, -7) from the top of the chart and eliminate answers that are not true: (A) becomes -7 = -3 - 4, which is true. Keep it. Keep (B): -7 = 2(-3) - 1 is true. Get rid of (C), which becomes -7 = 2(-3) + 2: -7 does not equal -4. Get rid of (D): -7 = 3(-3) - 3. -7 does not equal -12. Now use another pair just to test (A) and (B). Using (-1, -3), (A) gives -3 = -1 - 4, which is not true, so eliminate it, leaving only (B). The values (-1, -3) work: -3 = 2(-1) - 1.