Question

the table shows ordered pairs of the function $y = 16 + 0.5x$.

$\boldsymbol{x}$	$\boldsymbol{y}$
$-2$	$15$
$0$	$16$
$1$	$16.5$
$x$	$y$
$10$	$21$

which ordered pair could be the missing values represented by $(x, y)$?

• $(0, 18)$
• $(5, 19.5)$
• $(8, 20)$
• $(10, 21.5)$

Explanation:

Step1: Check (0,18)

Substitute \( x = 0 \) into \( y = 16 + 0.5x \).
\( y = 16 + 0.5(0) = 16 \). But the option has \( y = 18 \), so incorrect.

Step2: Check (5,19.5)

Substitute \( x = 5 \) into \( y = 16 + 0.5x \).
\( y = 16 + 0.5(5) = 16 + 2.5 = 18.5 \). Option has \( y = 19.5 \), incorrect.

Step3: Check (8,20)

Substitute \( x = 8 \) into \( y = 16 + 0.5x \).
\( y = 16 + 0.5(8) = 16 + 4 = 20 \). Matches, so check next to confirm.

Step4: Check (10,21.5)

Substitute \( x = 10 \) into \( y = 16 + 0.5x \).
\( y = 16 + 0.5(10) = 16 + 5 = 21 \). But the option has \( y = 21.5 \), incorrect.

Answer:

(8, 20)