Answer:
x=0; x=-2
Step-by-step explanation:
so first you do (x+2)^2 which is x^2+2x+4
4x^2 +8x +16 = 16
Subtract 16 from both sides
4x^2 +8x = 0
factor out 4x:
4x(x+2) = 0
Count backwards from 10 until you reach the number. for 8 you count 10,9,8 and for 3 you count 10,9,8,7,6,5,4,3. 8 is greater because it took <span>less </span>time to get there from 10. you could also count up from 0 (0,1,2,3 or 0,1,2,3,4,5,6,7,8). If you count from 0, the greatest is the one that takes the most amount of time
X=4 is the answer if you are looking for x
Answer:
The number is 623.
Step-by-step explanation:

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