To factor a cube (a^3-b^3) = (a-b)(a^2+ab+b^2)
8 is the cube of 2
r^3 is the cube of r.
So, a is 2 and b is r
(2-r)(2^2+2r+r^2)
(2-r)(4+2r+r^2)
Answer:
1320m^3
Step-by-step explanation:
Volume of a prism = Area x Cross Section
Area of a triangle = 1/2 x base x height
Cross section in this figure = 11m
Volume of triangular prism = 1/2 x 16 x 15 x 11
Volume = 1320m^3
I hope this helps you!! If you need more explaining, I'll be happy to add to my answer.
Answer:
20.4
Step-by-step explanation:
use trig relations with the angle 74˚
the sides we know are the hyp (74) and the adj side to 74˚ (x).
the trig function associated with hyp and adj is cos.
cos = adj/hyp.
cos 74˚ = x/74
0.27 = x/74
x = 20.39
x = 20.4
Answer:
The rock will take about 4.5 seconds to reach the river
Step-by-step explanation:
* lets study the situation of the rock
- The rock is dropped means the initial velocity is zero
- The motion is free fall under earth gravity
- The rock dropped from a bridge 320 feet above the river
- The equation of the pathway is h = -16t² + 320
- When the rock reach to the ground the height will be zero
* Now lets substitute h by zero in the equation to find t
∵ h = -16t² + 320
∵ h = 0
∴ 0 = -16t² + 320 ⇒ add 16t² to both sides
∴ 16t² = 320 ⇒ divide both sides by 16
∴ t² = 320/16 = 20
∴ t² = 20 ⇒ take √ for both sides
∴ t = √20 = 2√5 ≅ 4.5 seconds
* The rock will take about 4.5 seconds to reach the river
