Do i still add like terms in an equation, even when it says to subtract between the two coefficients?

Question

The question is;

Combine the like terms.

11x-9x = 18. Could you possibly walk me through this equation? Im unsure of what to do since there is a subtraction sign. Do i still add the coefficients? 

Answer 1

you can combine like terms by adding or subtracting the coefficients.

 

in this case you will subtract because there is a minus sign.

 

11x - 9x = 2x

 

2x = 18

 

x = 9