There are 8 possible outcomes when you throw a coin three times:

Out of these combination, the ones with exactly two heads are

So, 3 combinations out of 8 have exactly two heads. This means that the probability of having two heads with three coin throws is 3/8
Answer:

Step-by-step explanation:
Given


Required
Find PQR
Since both angles are supplementary, we have:

This gives:


Collect Like Terms


Divide through by 10

Substitute 20 for X in 


Answer:
49 red marbles
Step-by-step explanation:
We should first make 5/12 have a base of 84, so that'll be
(5*7)/(12*7)=35/84. So we have 35 blue marbles and all the rest are red, so 84-35=49
DUBS
Please consider giving me a brainliest! Thank you.
Answer:
3rd option
Step-by-step explanation:
The equation of a parabola in vertex form is
f(x) = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here (h, k ) = (- 1, - 25 ) , then
f(x) = (x - (- 1) )² - 25 , that is
= (x + 1)² - 25 ← expand using FOIL
= x² + 2x + 1 - 25
= x² + 2x - 24
Well, you want to solve for a. You first add the 4 to both sides.
3a-4<5
3a<9
Then you want to get a by itself so you divide both sides by 3. Since the 3 is positive you don't have to worry about switching the sign. It stays this way <
After you divided both sides by 3 you get a<3