Answer:
40,000 workers
Step-by-step explanation:
This question deals with simple rates proportion.
If it takes 20 years for X workers to complete a job,
if we double the amount of workers, we will take half the time.
hence to halve the time from 20 years to 10 years, we will need to double the amount of workers.
In this case we will need 20,000 workers x 2 = 40,000 workers
2/3 is it's simplified form
Answer:
y = 3, x = 3
Step-by-step explanation:
5x – 3y = 6
5x = 6 + 3y
x = (6 + 3y)/5
3x + 4y= 21
3x = 21 - 4y
x = (21-4y)/3
Using simultaneous equations:
(21-4y)/3 = (6 + 3y)/5
--> 105-20y = 18 + 9y
29y = 87
The answer is

.
Before we rationalize the denominator, we must simplify the numerator and denominator. We evaluate the square root on the top, and combine like terms on the bottom:

To rationalize the denominator, we multiply by the conjugate. The conjugate is found by making the imaginary term of the complex number, the i part, the opposite sign. The conjugate of -2-i is -2+i:
Answer:
9
Step-by-step explanation:
2/5 x 2 = 4/5
4/5 x 2, or 2/5 x 4 = 1 3/5
1 3/5 x 2, or 2/5 x 8 = 3 1/5
3 1/5 + 2/5, or 2/5 x 9 = 3 3/5