More STAAR problems.
Administered May 2018
Read each question carefully. For a multiple-choice question, determine the
best answer to the question from the four answer choices provided. For a
griddable question, determine the best answer to the question.
26.Which function is equivalent to f(x) = -4(x + 7)2 - 6?
F f(x) = −4x2 − 56x − 202
G f(x) = −4x2 + 14x + 43
H f(x) = −4x2 − 56x − 172
J f(x) = −4x2 + 190
Answer: F f(x) = −4x2 − 56x − 202
Look at the constant terms in the four choices. They are all different. Two of them make no sense at all.
The final term has to be (7)2 X (-4) - 6. That cannot be a positive number, so G and J are eliminated.
(7)2 X (-4) - 6 = -202. So it is Choice F.
Working it out would give you:
= -4(x2 + 14x + 49) - 6
= -4x2 - 56x - 196 - 6
= -4x2 - 56x - 202
22. A paper airplane was thrown from the top of a tall building. The height of the paper airplane above the ground can be found using the function y = −1.5x + 60, where x is the time in seconds the airplane has been in the air.
How many seconds did it take the paper airplane to reach the ground?
Record your answer and fill in the bubbles on your answer document.
Answer:
The graph isn't necessary. In fact, graphing a slope of -1.5 when the scale is 5 might even be confusing. (It's actually the same as if the scale was 1, as far as counting boxes goes.)
-60 = -1.5x
40 = x
After 40 seconds the airplane will reach the ground.
28. Which expression is equivalent to (q4)-3/q-15
F q27
G 1/q27
H q3
J 1/q3
Answer: H q3
(q4)-3/q-15 = q(4)(-3) - (-15) = q3
29. Which graph best represents a quadratic function that has only one zero?
Answer: B
A quadratic function with only one zero only touches the x-axis once. That means that the vertex must be on the x-axis itself as either a minimum or a maximum. That is choice B.
Choices A and C have two zeroes. Choice D has no zeroes. (Zero zeroes if you will.)
30. What is the solution set for −4x + 10 ≥ 5x + 55?
F x ≥ 5
G x ≥ 45
H x ≤ −5
J x ≤ −45
Answer: H x ≤ −5
−9x + 10 ≥ + 55
−9x ≥ 45
x ≤ −5
Don't forget to flip the inequality symbol around.
More to come. Comments and questions welcome.
More STAAR problems.
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