To calculate this you need to imagine triangle which points are:
boat
Top of lighthouse
Bottom of lighthouse
That triangle has 90 degrees angle at bottom of lighthouse. That means that we can use trigonometry to determine length between boat and bottom of lighthouse
tan(25) = 89/x
x = 89/tan(25)
x = 190.86
after rounding, the answer is D, 191 feet
The equivalent equation is x² + 20x = -102
<h3>
Simplification of quadratic equation</h3>
The equivalent equation can be obtained by factorizing or simplifying the given quadratic equation as shown below;
x² + 20x + 81 = -21
<em>collect similar terms together</em>
x² + 20x + 81 + 21 = 0
x² + 20x + 102 = 0
The equation can also be written as x² + 20x = -102
Thus, the equivalent equation is x² + 20x = -102
Learn more about simplification of quadratic equation here: brainly.com/question/1214333
Answer:
x axis
Step-by-step explanation:
We know the x value stays the same. If you were to graph the line y=3 and y=-3, you would see that it is a reflection over the x axis.