Answer:
- 20 + 8i
Step-by-step explanation:
Noting that i² = - 1
Given
[(6i + 9) + (4i - 5)] × 2i ← evaluate the terms inside the square bracket
= ( 6i + 9 + 4i - 5 ) × 2i
= (10i + 4) × 2i ← multiply each term in the parenthesis by 2i
= 20i² + 8i
= 20(- 1) + 8i
= - 20 + 8i
Answer:
b
Step-by-step explanation:
To best estimate the volume of the log, we assume that the diameter is the average of the diameters at both ends giving us 12 inches as the diameter. Thus, the radius is equal to 0.5 ft. The volume of the log is calculated through the equation,
V = πr²h = π(0.5 ft)²(10 ft) = 7.85 ft³
Volume of box with side length of 5 = 5^3 = 125
Volume of sphere = (4/3)*pi*5^3 = (4/3)pi * 125
Ratio = 125/(4pi/3)*125 = 1/(4pi/3) = 3/(4pi)
Answer: B
In a geometric progression:
a, b, c, d...
The common ratio can be obtained using:
b/a = c/b = d/c
b/a = 112 / 64 = 1.75
c/b = 196 / 112 = 1.75
d/c = 343 / 196 = 1.75
The common ratio = 1.75