Question

Use a graphing calculator to complete this table.

1) Evaluate the expression 2x + 2 starting at 5, ending at 20, and stepping by 5.
X Y1
5
10
15
20

Answer 1

`\begin{array}\cline{1-2}\vphantom{\frac12} x & y \\\cline{1-2}\vphantom{\frac12} 5 & 12 \\\cline{1-2}\vphantom{\frac12} 10&22\\\cline{1-2}\vphantom{\frac12} 15&32\\\cline{1-2}\vphantom{\frac12}20&42\\\cline{1-2}\end{array}`

Explanation:

To evaluate the expression 2x + 2 starting at 5, ending at 20, and stepping by 5, substitute the values of x given in the table into the expression.

`\begin{aligned}x=5 \implies y&=2(5)+2\\y&=10+2\\y&=12\end{aligned}`

`\begin{aligned}x=10 \implies y&=2(10)+2\\y&=20+2\\y&=22\end{aligned}`

`\begin{aligned}x=15 \implies y&=2(15)+2\\y&=30+2\\y&=32\end{aligned}`

`\begin{aligned}x=20 \implies y&=2(20)+2\\y&=40+2\\y&=42\end{aligned}`

Enter the corresponding y-values into the table.

Therefore, the completed table is:

`\begin{array}c\cline{1-2}\vphantom{\frac12} x & y \\\cline{1-2}\vphantom{\frac12} 5 & 12 \\\cline{1-2}\vphantom{\frac12} 10&22\\\cline{1-2}\vphantom{\frac12} 15&32\\\cline{1-2}\vphantom{\frac12}20&42\\\cline{1-2}\end{array}`

`\hrulefill`

To use a graphing calculator to complete the table:

• Graph the line y = 2x + 2.
• Locate the points on the line where x equals the values given in the table.
• For each point, trace horizontally to the y-axis and read the corresponding y-value.
• Place the found y-values into the table.

(See attachment).