Answer:
15/4 and 45/4
Step-by-step explanation:
Let x and y be the numbers
x = 3y
x+ y = 15
Substitute the first equation in to the second equation
3y+y = 15
4y = 15
y = 15/4
x = 3(15/4)
x = 45/4
The two numbers are 15/4 and 45/4
Answer:
21 feet
Step-by-step explanation:
Given :
Height of the tripod above the ground = 5 ft
Elevation = 8°
Distance of the tree from the tripod = 120 ft
Therefore from the figure, we can find the height of the tress as:


∴ BC ≈ 16
Therefore, CE = BC+BE
= 16 + 5
= 21
Therefore the height of the tree is 21 feet.
Formula of the Volume of a hemisphere:
V =


r³
144

=


r³
Multiply by 3 to cancel fraction in the right side
144

× 3 = 2

r³
432

= 2

r³
Divide by 2

on either sides to isolate r³

=

r³
2

and

cancel out
216 = r³
Take cube root to find the radius
![\sqrt[3]{216}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7B216%7D%20)
=
![\sqrt[3]{r^3}](https://tex.z-dn.net/?f=%20%5Csqrt%5B3%5D%7Br%5E3%7D%20)
6 = r
Radius is 6 unitsThe formula of the surface area of a hemisphere is:
S.A = 2

r² +

r²
=

(6)² +

(6)²
=2

× 36 + 36

= 72

+ 36

= 108

units² (in terms of

)
≈ 339.12 units²
Surface area = 108
units