102=8a+5a-3a

I add 8a and 5a first to get 13 and then add 3?

No.

Subtract 3a.

102 = 10a

8a+5a=13a=3a=10a Divide 102/10?

Or would the answer be 10a because 8a 5a and 3a are all like terms

To find the value of a,divide both sides by 10.

10a = 102
a = 102 / 10
a = 10.2

To solve the equation 102 = 8a + 5a - 3a, you can simplify it by combining like terms.

First, combine the coefficients of 'a'. Add 8a, 5a, and -3a together to get 10a. The equation now becomes:

102 = 10a

Next, to solve for 'a', you need to isolate it on one side of the equation. Since 'a' is multiplied by 10, you can divide both sides of the equation by 10 to get:

102/10 = 10a/10

This simplifies to:

10.2 = a

Therefore, the value of 'a' is 10.2.