Assuming that you mean to put n instead of 5, this is demonstrating The Identity Property.
The identity property is the property that states that by adding 0 to a number, you don't change the value. For example, 510 + 0 = 510.
17) replace the given number for "x" and evaluate
a) x² + 2x + 1 ; when x = 3
3² + 2(3) + 1
= 9 + 6 + 1
= 16
b) x² + 2x + 1 ; when x = -4
(-4)² + 2(-4) + 1
= 16 - 8 + 1
= 9
c) x² + 2x + 1 ; when x = 3
(-22.872)² + 2(-22.872) + 1
= 523.128384 - 45.744 + 1
= 478.384384
18) The dependent variable is affected by the other variable and is the "output" The independent variable is the input.
a) y = 3x - 5; "x" is the independent variable
b) the time of day is the independent variable (you would input the time of day to calculate the temperature).
19) Let the x-axis represent the length of the lumber cut off and the y-axis represent the length of the lumber remaining.
