Try each question before choosing Check answer. Guide question labels stay the same when you shuffle the bank. 1 written response appears below the bank, with model answers for self-review; these are not automatically graded. Follow any rounding instruction in the question.
Guide question labels stay the same when the order changes. Check answers when you are ready to review.
Written self-checks are below the question bank and are excluded from the automatic score.
Written responses are self-review exercises.
Saved on this browser and device; clearing browser data removes progress.
Compare the reasoning as well as the answer. Equivalent valid methods are welcome. A referenced example provides a targeted repair route.
The drill
Your practice is saved on this device.
Question 2
Guide question E4.2
A squared equation produces candidates 4 and −3 for = x. Which candidates satisfy the original equation?
Enter an integer, decimal or fraction without units. Use up to 5 characters, or 6 including a leading minus.
Why this answer
Only 4.
The principal square root is nonnegative, so a negative right side cannot work. At x = 4,= 4. At x = −3,= 3 ≠ −3. Both candidates satisfy the squared equation, but only 4 satisfies the original. This is why substitution belongs in the unsquared equation. Review Example 4.02.
How many real solutions does (x2 − 16)/(x − 4) = 8 have?
Enter an integer, decimal or fraction without units. Use up to 5 characters, or 6 including a leading minus.
Why this answer
0.
The domain excludes x = 4. Cancelling the common factor for allowed inputs gives x + 4 = 8, whose only candidate is 4. Since that candidate is excluded, there is no solution. A graph that appears to connect through the hole at (4, 8) does not change the original domain. Review Example 4.03.
A circle has radius centimeters. Find its area to the nearest tenth of a square centimeter.
Enter an integer, decimal or fraction without units. Use up to 5 characters, or 6 including a leading minus.
Why this answer
94.2 cm2.
Use A = πr2= π()2= 30π ≈ 94.2477796, which rounds to 94.2. Enter 30*pi, not a rounded radius that will subsequently be squared. The exact ratio A/π = 30 is the useful check. Review Example 4.08.
Each shuttle holds at most 12 passengers. What is the least number of shuttles needed for 137 passengers?
Enter an integer, decimal or fraction without units. Use up to 5 characters, or 6 including a leading minus.
Why this answer
12.
137/12 ≈ 11.4167, but the count must be an integer with enough seats. Eleven shuttles hold only 132 passengers; twelve hold 144. The first feasible count is 12, even though ordinary rounding of the quotient would give 11. Review Example 4.10.
Write your complete response before opening the model answer. Compare both your answer and your reasoning.
Guide question E4.1
The exact solution of an equation is 5/8. Give both an exact fraction entry and an exact decimal entry for a numeric-response field.
Show model answerHide model answer for question E4.1
5/8 and .625.
Because 5 ÷ 8 = 0.625, the fraction and terminating decimal are exact equivalents. Both fit the entry conventions; 0.625 also fits. Do not attach units or a percent sign unless the quantity itself has first been converted to the requested percent number. Review Example 4.04.