Released STAAR Algebra I EOC · 2026 · Item 15 · 1 point

Walkthrough: Algebra I 2026, Item 15

A.9C · Exponential Functions · unscored study

A decreasing curve on a grid with x from about negative 1.5 to 2 and y from 0 to 15. It passes through negative 1, 10 and 0, 4, and approaches the x-axis as x increases. — Graph of an exponential functionOriginal visual from the released STAAR test.

The graph of the exponential function shown on the grid passes through the points $(-1, 10)$ and $(0, 4)$ . Which function is represented by the graph?

$g(x) = 4\left(\frac{2}{5}\right)^x$
$g(x) = 4\left(\frac{1}{2}\right)^x$
$g(x) = \frac{2}{5}(4)^x$
$g(x) = \frac{1}{2}(4)^x$

1. Understand the question

Use the two labeled points. The point where $x = 0$ gives $a$ ; the ratio between the points gives $b$ .

Try the question on your own first, then reveal one step at a time.

2. Solve it step by step

Practice released items for this skill Back to the lesson

Question, artwork, answer key and rationale: Texas Education Agency released STAAR test. Walkthrough steps written by TEKSForge. Studying here does not change your mastery or scores.