Answer:
x = 2.6, x = -1.6
Step-by-step explanation:
If we compare the graph to points (-1, 2) and (2, 2) [see blue lines on attachment], we can determine that the scale of the y-axis is 1 square per 1 unit. (This is different from the scale of x-axis, which is 2 squares per unit).
Therefore, to use the graph to estimate the x-value when y = 4, count 4 square up the y-axis from 0, then trace along the horizontal line until you meet the curve. Then trace down to the x-axis and read the values of x. (shown by the red lines on the attachment).
So the approximate value of x is -1.6 and 2.6 when y = 4.
The actual answer can be calculated as follows:
x² - x = 4
⇒ x² - x - 4 = 0
Use the quadratic formula:
[tex]x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}[/tex]
[tex]\implies x=\dfrac{-(-1)\pm\sqrt{(-1)^2-4(1)(-4)}}{2(1)}[/tex]
[tex]\implies x=\dfrac{1\pm\sqrt{17}}{2}[/tex]
[tex]\implies x=2.6,x= -1.6 \sf \ (1 \ dp)[/tex]
