The correct answer choice is the one that has a value of 4 or −4 when x = 3.(A): 3 x − 10 = 3(3) − 10 = 9 − 10 = −1. This is not 4 or −4. Discard (A).(B): 4 x − 7 = 4(3) − 7 = 12 − 7 = 5. This is not 4 or −4. Discard (B).(C): 6 x − 17 = 6(3) − 17 = 18 − 17 = 1 . This is not 4 or −4. Discard (C).(D): x^2 − 5 = 3^2 − 5 = 9 − 5 = 4. Now you know that x^2 − 5 could be g(x), so (D) is correct.Checking (E) to be sure, x^2 − 3 = 32 − 3 = 9 − 3 = 6. This is not 4 or −4.23 . A
Since line n is perpendicular to the x-axis, and the y-axis is perpendicular to the x-axis, line n
is parallel to the y-axis, and every point on line n has the same x-coordinate. You know that
one point on line n has the coordinates (4,5). The x-coordinate of this point is 4. So the x-
coordinate of every point on line n is 4. The equation of line n is x = 4.
24 . B
The mean is the average. The average formula is
When you know the average and the number of terms, you can find the sum of the terms by
rearranging the average formula in the form Sum of the terms = Average × Number of terms.
So the sum of the scores on all 5 tests was 84 × 5 = 420. The sum of the scores on the first 4
tests was 87 × 4 = 348 . So the score on the fifth test is the sum of the scores on all 5 tests
minus the sum of the scores on the first 4 tests. Then the score on the fifth test is 420 − 348 =
72.25 . A
Use the calculator. If cos x = 0.34, then x = arccos 0.34 ≈ 70.123°. Then