Glencoe Math: Course 2, Volume 2
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Glencoe Math: Course 2, Volume 2 View details
7. Subtract Linear Expressions
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Exercise 14 Page 408

To find the additive inverse of a linear expression, you can multiply each term of the expression by -1.

A

Practice makes perfect
We want to find out which of the given linear expressions equals the following one. (5x-7)-(3x-4) To do so, we will simplify the above expression. First, let's find the additive inverse of the linear expression within the second set of parentheses. To do so, we can distribute -1 into the second set of parentheses. When we do so, we multiply each term of that linear expression by -1.
(5x-7)-(3x-4)
(5x-7)+((-1) * 3x-(-1) * 4)
(5x-7)+(-3 x-(-4))
(5x-7)+(-3 x + 4)
Now, let's identify which, if any, terms can be combined. Remember, only like terms — constant terms or terms with the same variable — can be combined. ( 5x - 7)+( -3 x + 4) In this case, we have two x-terms and two constants. Let's arrange the like terms in columns. Then, let's perform the addition. 5 x - 7& (+) -3 x +4& 2 x -3& Therefore, we get the following result. (5x-7)-(3x-4) = 2x-3 Comparing the above result to the given expressions, we see that the initial expression equals the one in answer A.