13a+9b-2a-4b
13-2 = 11
9-4 = 5
so
11 a + 5 b
13a + 9b -2a -4b
13a -2a + 9b - 4b
= 11a + 5b
To simplify the expression 13a + 9b - 2a - 4b, we need to combine the like terms.
Like terms are terms that have the same variables raised to the same powers. In this expression, "a" and "b" are the variables.
First, let's combine the "a" terms. We have 13a - 2a. To combine these terms, we subtract the coefficients: 13 - 2 = 11.
Next, let's combine the "b" terms. We have 9b - 4b. Again, we subtract the coefficients: 9 - 4 = 5.
Putting it all together, the simplified expression is 11a + 5b.