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




$x$
$y$

-4
14

-2
15

0
16

1
16.5

$x$
$y$

10
21






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


A$(5, 19.5)$
B$(8, 20)$
C$(0, 18)$
D$(10, 21.5)$

Verified Answer :

  • Identify the function \(y = 16 + 0.5x\) and test each provided ordered pair \((x, y)\) by substituting the \(x\)-coordinate.
  • Calculate the \(y\)-value for \(x=5, 8, 0, 10\).
  • Find that the only pair matching the equation is \((8, 20)\) because \(16 + 0.5(8) = 20\).
  • Conclude that the correct option is \(\boxed{b}\).

Explanation

  1. Problem Analysis

The objective is to identify which of the given ordered pairs \((x, y)\) satisfies the linear equation \(y = 16 + 0.5x\). An ordered pair \((x, y)\) is a solution to an equation if substituting the given \(x\)-value into the equation results in the corresponding \(y\)-value. We will test each provided option one by one.

  1. Evaluating the Options

We evaluate each option by substituting the given \(x\)-coordinate into the function \(y = 16 + 0.5x\):

AFor the pair \((5, 19.5)\):

\[y = 16 + 0.5(5) = 16 + 2.5 = 18.5\]
Since \(18.5 eq 19.5\), this pair does not satisfy the function.

BFor the pair \((8, 20)\):

\[y = 16 + 0.5(8) = 16 + 4 = 20\]
Since the result matches the \(y\)-value of the pair (\(20 = 20\)), this pair satisfies the function.

CFor the pair \((0, 18)\):

\[y = 16 + 0.5(0) = 16 + 0 = 16\]
Since \(16 eq 18\), this pair does not satisfy the function.

DFor the pair \((10, 21.5)\):

\[y = 16 + 0.5(10) = 16 + 5 = 21\]
Since \(21 eq 21.5\), this pair does not satisfy the function.

  1. Conclusion

Based on our calculations, only the pair \((8, 20)\) satisfies the given equation \(y = 16 + 0.5x\). Therefore, the correct option is b).

Examples

In real-life scenarios, linear relationships are common, such as calculating the total cost of a service. For example, if a taxi charges a base fee of \(\$16\) plus \(\$0.50\) for every mile traveled, the total cost \(y\) for traveling \(x\) miles is modeled by \(y = 16 + 0.5x\). Checking ordered pairs ensures that the billing system is accurate and consistent with the defined rates. If you travel 8 miles, the total cost would be \(16 + 0.5(8) = \boxed{\$20}\).