Writing Equations from Tables Teacher Twins 2014 Warm

Warm Up Look at the input/output table below. What is happening to the input to give you the output? Input 900 950 1242 Output 917 967 1259 Input + 17 = Output

Look at the following table. What is happening to x that gives you y? By looking at the table X 1 3 5 7 Y 7 9 11 13 you can see that when you add 6 to x you get the y value. We can write an equation using 2 variables for this table. The equation for the table is : y = x + 6

Give the equation for the following table: Example 1: X Y -1 -0. 5 0 0 2 1 5 2. 5 When you look at the x and y values, you see that y is half of x.

Give the equation for the following table: Example 2: X Y -1 1 0 2 2 4 5 7 When you look at the x and y values, you see that y is two more than x. The equation for the table is: y = x + 2

Give the equation for the following table: Example 3: X Y -2 -1 0 3 2 7 5 13 When you look at this table you can see that there are 2 operations that will be performed on x to give you the y value. The x is multiplied by 2 and then added to 3. Y = 2 x + 3

Give the equation for the following When you look at this table you table: Example 4: X Y -1 -7 0 -4 2 2 5 11 can see that there are 2 operations that will be performed on x to give you the y value. The x is multiplied by 3 and then subtracted by 4 or added to – 4. The equation for the table is: y = 3 x -4 or y = 3 x + - 4

Practice. Write the equation for each table. 1). X -1 1 4 7 Y -7 -5 -2 1 3). X -1 1 2 4 Y 4 -4 -8 -16 2). Y=x-6 Y = - 4 x 4). X Y -1 -2 0 1 2 7 5 16 X 0 1 2 3 Y -2 0 2 4 Y = 3 x + 1 Y = 2 x -2

Example 5: Complete the table for the equation or rule. X Y= 2 x + 1 Y -1 0 1 2 Put in each value of x and solve for y. Then record the value of y in the chart.

Example 5 Complete the table for the equation or rule. X Y= 2 x + 1 Y -1 Y = 2(-1) + 1 -1 0 Y = 2(0) + 1 1 1 Y = 2(1) + 1 3 2 Y = 2(1) + 2 4

Practice: Complete the tables for the equation or rule. 1). X Y= X + 15 Y -1 0 1 2 2). X -2 -1 1 2 Y= -6 X Y

Practice: Complete the tables for the equation or rule. 1). X Y= X + 15 Y -1 Y= -1 + 15 14 0 Y = 0 + 15 15 1 Y = 1 + 15 16 2 Y = 2 + 15 17 2). X Y= -6 X Y -2 Y= -6( -2) 12 -1 Y = -6(-1) 6 1 Y = -6(1) -6 2 Y = -6(2) -12

Closure Create your own table and write an equation for it.