Answer:
The atomic mass
Step-by-step explanation:
The decimal at the bottom of an element represents how much one atom of that element weighs.
Answer: Second option.
Step-by-step explanation:
It is important to remember the Distributive Property in order to solve this exercise.
The Distributive property states that:

In this case you have the following expression provided in the exercise:

Then, in order to write this expression in another way, you can apply the Distributive property. Multiply each number inside the parentheses by "t".
Applying this procedure, you get:

Notice that this expression matches with the one shown in the the second option.
Answer:
add 3 to both sides of the equal sign
Step-by-step explanation:
to solve the equation you would have to add three
that is because you have to do inverse operations
and you would add because the opposite of subtracting is adding
so solving it would look like this
x - 3 = 12
+3 +3
x = 15
this is how you check the answer:
15 - 3 = 12
+3 +3
The solutions appear to be
{π/2, 2π/3, 4π/3}.
_____
Replacing sin(2x) with 2sin(x)cos(x), you have
2sin(x)cos(x) +sin(x) -2cos(x) -1 = 0
sin(x)(2cos(x) +1) -(2cos(x) +1) = 0 . . . . factor by grouping
(sin(x) -1)(2cos(x) +1) = 0
This has solutions
sin(x) = 1
x = π/2and
2cos(x) = -1
cos(x) = -1/2
x = {2π/3, 4π/3}