Question

How do you find the sum or difference of $(2x - 2y + 1) - (3y + 4x)$?

Answer 1

Hint: First of all take the given expression and we will open the brackets and will combine the like terms and will simplify for the resultant required value. Remember when there is a negative sign outside the bracket then the sign of all the terms inside the bracket changes.

Complete step-by-step solution:
Take the given expression: $(2x - 2y + 1) - (3y + 4x)$
Open the bracket multiplying the term outside with the terms inside the bracket.
$ \Rightarrow 2x - 2y + 1 - 3y - 4x$
Arrange the like terms together, like terms are the terms with the same variable and its power.
$ \Rightarrow \underline {2x - 4x} - \underline {2y - 3y} + 1$
Combine the like terms, when you add one positive term and one negative term you have to do subtraction and give sign of the bigger number to the resultant value.
$ \Rightarrow - 2x - 5y + 1$
This is the required solution.

Hence the correct answer is $ - 2x - 5y + 1$.

Note: Be very careful while simplification of the terms. When you open the brackets and there is a negative sign outside the bracket then the sign of the terms inside the bracket will be changed. Positive terms will become negative and negative terms become positive. Also, remember when there is a positive sign outside the bracket then the sign of the terms inside the bracket do not change and remains the same.