Answer:
<em>x=3</em>
Step-by-step explanation:
<u>Angles and Lines</u>
We must recall:
- The sum of the internal angles of a triangle is 180°
- Two linear angles add up to 180°
The image shows a triangle and the extension of its base to form two linear angles.
Note from the triangle, angle R is what it takes to get to 180°:

From the line SQ, angle R what it takes to get to 180°. Thus:

Equating:

Subtracting 180 and simplifying:


Dividing by 19:
x=3
Answer
Find out the how many pounds of metal are in 1,950 lb of ore .
To proof
let us assume that the pounds of metal are in 1,950 lb of ore be x .
As given
In an ore, 9.8% of its total weight is metal.
ore weight = 1,950 lb
9.8% is written in the decimal form

= 0.098
Than the equation becomes
x = 0.098 × 1950
x = 191.1 pounds
Therefore the 191.1 pounds of metal are in 1,950 lb of ore .
Hence proved
A stuntman jumping off a 20-m-high building is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film him between 15 m and 10 m above the ground. For which interval of time should the camera film him?
Answer:

Step-by-step explanation:
Given:
A stuntman jumping off a 20-m-high building is modeled by the equation
-----------(1)
A high-speed camera is ready to making film between 15 m and 10 m above the ground
when the stuntman is 15m above the ground.
height
Put height value in equation 1





We know that the time is always positive, therefore 
when the stuntman is 10m above the ground.
height
Put height value in equation 1







Therefore ,time interval of camera film him is 
Answer: the answer is a
Step-by-step explanation:
3t+12-4t-6=-4
-t=-4+6-12
-t=-10
t=10
That's your answer.