NBT NBT Algebra and Functions 5

Question 1

What are the x-intercepts of f(x) = x² − x − 6?

Accepted Answer

x = 3 and x = −2

Answer

x² − x − 6 = (x − 3)(x + 2) = 0 gives x = 3 and x = −2.

Question 2

A store sells notebooks for $n each. After a 20% discount, Jess pays $12. What is n?

Accepted Answer

$15

Answer

0.80n = 12 → n = 15.

Question 3

If h(x) = √(x − 3), what is the domain of h?

Accepted Answer

x ≥ 3

Answer

The expression under the square root must be non-negative: x − 3 ≥ 0, so x ≥ 3.

Question 4

The graph of y = f(x) is shifted 4 units left and 2 units down. Which represents the new function?

Accepted Answer

y = f(x + 4) − 2

Answer

Left shift by 4 replaces x with x + 4; down shift by 2 subtracts 2 from the output.

Question 5

If 2x − y = 7 and x + y = 5, what is the value of x?

Accepted Answer

4

Answer

Adding the equations gives 3x = 12, so x = 4.

(NBT) National Benchmark Test Practice Test