We have:

Thus:

Adding

gives:

Factoring gives:

Thus, we have:

or

.
Note that because

, there will be no solutions

of the form

for positive integer

and solution

. So we find the basic values of

giving

.
For

with positive

,

(this can be seen easily from the unit circle. But

, a contradiction. So we examine the case in which

.
In this case,

. So this is the only solution to this equation.
Substituting this back in, we have

, as desired. So this is a valid solution.
Thus,

.
Answer:
1 and 7
Step-by-step explanation:
21: 1, 3, 7, 21
28: 1, 2, 4, 7, 14, 28
Common: 1, 7
Answer:

Step-by-step explanation:

Just flip your fraction around and your answer will be 10/11
The equation given is:
10 5/18 - 8 5/6
Turn the equations to improper fractions
[10*18 +5] = 185
[8 * 6 + 5]= 53
185/18 - 53/6
[185 - 159]/18 = 26/18
26/18 = 1 8/18.