<span>x in (-oo:+oo)
(8/9)*x = (4/9)*x+8 // - (4/9)*x+8
(8/9)*x-((4/9)*x)-8 = 0
(8/9)*x+(-4/9)*x-8 = 0
4/9*x-8 = 0 // + 8
4/9*x = 8 // : 4/9
x = 8/4/9
x = 18
x = 18
</span>
Well the first obvious thing is that the axis of symmetry is 0.5, so we can automatically cross out (C).
All the answers have the correct vertex, so lets find the formula for the function.
Fortunately, from my point of view, I can see two points that have their coordinates as integers, (-1, -3) and (2, 3), we can plug these into the already given "formulas" in the options (A), (B), and (D).
Out of the three choices, the formula in option (D) satisfies both coordinates, thus option (D) is correct.
ANSWER;
Variables
Variables are factors in an experiment that can change. There are three types of variables in a scientific experiment: independent, dependent and controlled variables. The scientist changes the independent variable in a systematic manner and measures the effects of this change on the dependent variable. The other variables are called controlled variables because the experiment is designed to keep them at an unchanging value, known as "controlling" a variable. A valid experiment should have only one independent variable.
