Answer:
52
Step-by-step explanation:
for every 4 pencils there is 1 eraser. 4/1=208/x
4x=208
x=52
Answer:
What is missing is -5x - 20
Step-by-step explanation:
To find this, simply solve for the parenthesis as if it were a variable of its own. This will allow you to see exactly what is missing.
8x - (x - 20) = 2x - (_______)
8x - x + 20 = 2x - (_______)
7x + 20 = 2x - (_______)
5x + 20 = - (_______)
-5x - 20 = (_______)
So the answer for the parenthesis is -5x - 20
Answer:

The world population at the beginning of 2019 will be of 7.45 billion people.
Step-by-step explanation:
The world population can be modeled by the following equation.

In which Q(t) is the population in t years after 1980, in billions, Q(0) is the initial population and r is the growth rate.
The world population at the beginning of 1980 was 4.5 billion. Assuming that the population continued to grow at the rate of approximately 1.3%/year.
This means that 
So


What will the world population be at the beginning of 2019 ?
2019 - 1980 = 39. So this is Q(39).


The world population at the beginning of 2019 will be of 7.45 billion people.
Answer:
x=9
Step-by-step explanation:
10x - 11 -4x = 43
6x -11 =43
6x = 54
x=9
Answer:
- Circumference = 69.14cm
- Area = 380.29cm²
Step-by-step explanation:
Circumference.
Circumference of a circle is calculated by the formula:
= Pie * diameter
= π * diameter
= 22/7 * 22
= 69.14 cm
Area
Area of circle:
= Pie * radius ²
Radius = diameter/2
= 22/2
= 11 cm
Area = 22/7 * 11²
= 22/7 * 121
= 380.29 cm²