Area of a circle is directly proportional to the square of radius of the circle while the circumference is proportional to the radius of the circle. This means that if the radius of a circle is increased x times, then its area will be increased to x^2 times the original area, and the circumference will increase to x times the original circumference.
Thus when the radius is doubled, or in other words if radius mad 2 time the original radius, the area of circle will become 2^2 = 4 time the original area. The circumference will become 2 times the original circumference.
We can calculate exact area and circumference of a circle from its radius using the following equations:
Area of circle = (pi/4)*r^2
Circumference of circle = 2*pi*r
Where r is the radius of the circle.
I know this is a lot, sorry.
17)
x² + 8 = -8
x² = -8 - 8
x² = 16
x = ±√-16
x = ±√16i
x = <span>±4i
</span>
18)
x² + 5 = -3
x² = -3 - 5
x² = -8
x = ±√-8
x = ±√8i
x = ±2√2i
19)
x² + 3 = 0
x² = -3
x = ±√-3
x = <span>±</span>√3i
hope this helps, God bless!
Answer:
x =-4
Step-by-step explanation:
4x+9 = -2x-15
Add 2x to each side
4x+2x +9 = -2x+2x-15
6x+9 = -15
Subtract 9 from each side
6x +9-9=-15-9
6x = -24
Divide each side by 6
6x/6 = -24/6
x = -4
Let x = number of adult tickets sold
Let x-53 = number of student tickets sold
x + x -53 = 697
2x - 53 = 697.
Add 53 to both sides to get:
2x = 750
Divide both sides by 2 to get:
x = 375
375 adult tickets were sold.
Answer:
16 people
Step-by-step explanation:
Given that :
Number of people to tour = 80
Number per group = 16
Number of groups = 4
Total number of people who make up the entire groups :
Number per group * number of groups
16 * 4 = 64
The number of people in the last tour group :
80 - 64
= 16 people
