The probability that Gina randomly selected two red marbles is 1/19
<u>Explanation:</u>
Total number of marbles = 7 + 5 + 8
= 20
The probability of getting two red marbles in the fraction form is given as:
P(first red marble) = number of red marbles / total number of marbles
P(first red marble) = 
P(second red marble) = number of red marbles after 1 white marble is removed / total number of marbles after 1 red marble is removed.
P(first red marble) = 
P(two red marbles) = P(first) X P(second)
= 
= 
Therefore, the probability that Gina randomly selected two red marbles is 1/19
The true statement is that minerals come from the ground as crystals. Hope this helps!
We have
so this is indeed a difference of squares. Factorizing would give
making the answer D.
We can further factor the first term here and write
but that's clearly out of the scope of this question.
Answer:
<h2>The first one is the answer</h2>
Step-by-step explanation:
Hope im correct can you brainliest me?
To obtain the total surface we have to calculate the surface of the 4 triangles and add up the areas (remember that the area of a triangle is (b*h)/2 , b is the base, h is the height ).
We will caculate first the area of the base triangle for that we considerer the fact that it is an equilateral triangle with sides of lenght 6 cm, now we calculate the height, I am going to draw please wait a moment
using the pythagorean theorem we have that
![\begin{gathered} h^2=6^2cm^2-3^2\operatorname{cm}=27cm^2 \\ h=\text{ }\sqrt[]{27\text{ }}cm \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20h%5E2%3D6%5E2cm%5E2-3%5E2%5Coperatorname%7Bcm%7D%3D27cm%5E2%20%5C%5C%20h%3D%5Ctext%7B%20%7D%5Csqrt%5B%5D%7B27%5Ctext%7B%20%7D%7Dcm%20%5Cend%7Bgathered%7D)
Then, the area of the triangle is 6*h/2 = 3h = 15.59 cm^2.
Now we calculate the area of the other 3 triangles, notice that those triangles have the same base and height so we will calculate for one of them and multiply by 3. From the image we know that the height is 15cm and the base is 6 cm so the area is 45cm^2, and 45*3 cm^2 = 135cm^2.
Finally we add up all the areas:
