Which of these is equal to sin 21°?

The first man has 7 oranges and the other man has 5 oranges

Step-by-step explanation:

System of Equations

To solve the problem, we set the variables:

x = number of oranges of the first man

y = number of oranges of the other man

If the other man gives one orange to the first man:

x + 1 = one more orange for the first man

y - 1 = one less orange for the second man

The first condition is: if the other man gives one orange to the first man, the latter would have double oranges:

x + 1 = 2 (y - 1)

Operating:

x + 1 = 2y - 2

x = 2y - 3       [1]

The second conditions states if the first man gives one orange to the other man, they would have the same number of oranges:

x - 1 = y + 1       [2]

Substituting [1] in [2]

2y - 3 - 1 = y + 1

Subtracting y and operating:

2y - y - 4 = 1

y = 1 + 4

y = 5

From [1]:

x = 2(5) - 3

x = 7

The first man has 7 oranges and the other man has 5 oranges