Proof (reasons are given in brackets):
Consider 
, 
:
(given)
(vertically opposite angles are equal)
(given)
(SAS)
Hope this helps :)
The best step to do next is to add 80 to both sides of equation:
5 ( x² + 8 x ) + 80 = 14 + 80
and since 80 = 5 · 16
5 ( x² + 8 x + 16 ) = 94 Answer : B )
After that we will continue like this:
5 ( x + 4 )² = 94
( x + 4 )² = 18.8 ... etc
If x = -b/2a, then 2a = -b / x so a = -b / 2x or a = b / -2x
So the denominator is -2x because it has to take the minus sign that the numerator refused to take ;-)
Answer:
Option D. two complex roots
Step-by-step explanation:
we know that
In a quadratic equation of the form 
the discriminant D is equal to
in this problem we have
so
substitute the values
The discriminant is negative
therefore
The quadratic equation has two complex roots
Answer:
Whether or not a given isotope is radioactive is a characteristic of that particular isotope. Some isotopes are stable indefinitely, while others are radioactive and decay through a characteristic form of emission. As time passes, less and less of the radioactive isotope will be present, and the level of radioactivity decreases. An interesting and useful aspect of radioactive decay is half-life, which is the amount of time it takes for one-half of a radioactive isotope to decay. The half-life of a specific radioactive isotope is constant; it is unaffected by coTnditions and is independent of the initial amount of that isotope.
