Answer:
x = 16
Step-by-step explanation:
5 = 1/2(x) - 3
Add 3 to both sides.
8 = 1/2(x)
Rewrite for clarity.
1/2(x) = 8
x/2 = 8
Multiply both sides by 2.
x = 16.
Proof:
5 = 1/2(x) - 3
Substitute variable.
5 = 1/2(16) - 3
Multiply 1/2 and 16.
5 = 8 - 3
Subtract 3 from 8.
5 = 5
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:
Answer:
<u>Usain Bolt's average speed in yards per second was 11.4</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
World record of Usain Bolt = 9.589 seconds
Distance of the world record = 100 meters
1 yard = 0.9144 meters ⇒ 100 meters = 109.36 yards
2. What was Usain Bolt's average speed in yards per second?
Let's recall that the formula of speed is:
Speed = Distance/Time
Replacing with the values we know:
Usain Bolt's Speed = 109.36/9.589
<u>Usain Bolt's Speed = 11.4 yards per second (Rounding to one decimal place)</u>
One and tens ar the didgets