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:
10 kph
Step-by-step explanation:
Find the speed of the current of the river.
20/(20 - c) + 180/(20 + c) = 8
20(20 + c) + 180(20 - c) = 8(400 - c^2)
8c^2 - 160c + 800 = 0
8(c^2 - 20c + 100) = 0
8(c - 10)^2 = 0
c = 10
The speed of the current of the river is 10 km/hour.
Answer:
Step-by-step explanation:
<em>OR</em>
Information on trigonometric ratios
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Answer:
0.21
Step-by-step explanation:
if you write it as a fraction it would be 21/100
and if that is made to a decimal it would be 0.21 .
