The steps for adding mixed numbers with unlike denominators are very the steps for adding fractions with unlike denominators.

ANSWERS:
similar to
different from

the answer is "different from"

It will be different from

The equations that are used to determine the values of x and y are 3x - y = 9 and 4x + y = 5. According to the degrees of freedom rule, the number of unknown variables should be equal to the number of independent equations in order to solve the problem. In this respect, we can use elimination in order to solve the equations

3x - y = 9
4x + y = 5

we add these two in order to eliminate y, thus,

7x = 14
x = 2 

from equation 1, 3*2 - 9 = y ; y = -3. hence the solution set is equal to (2,-3). The answer to this problem would have to be C.