Respuesta :

Answer: 1 3/10a+19

Step-by-step explanation:

Ok so first you have to open the parenthesis. Since the sign to the left of both the parenthesis is positive we can just normally open the parenthesis  .

We get: 1/2a+12+4/5a+7

We need to convert the denominators of  1/2a and 4/5a so we can add them together

1/2a=5/10a

4/5a=8/10a

Now we can add the a variables together.

5/10a+12+8/10a+7=

13/10a+12+7

Then add 12 and 7 together:

13/10a+19 = 1 3/10a+19

Keep in mind: If the sign to the left of the leftmost parenthesis is negative then the sign inside the parenthesis is negative.

For example when opening this parenthesis: (2+3/x)-(2+3x) the sign is negative so the opening parenthesis is -2-3x.