Does the associative property always, sometimes, or never hold for subtraction. explain your reasoning using examples and non-examples! !

You should remember that if the minus sign is before the parentheses, you need to distribute it, otherwise, you can always use it.

Step-by-step explanation:

The associative property says that:

A + (B + C) = (A + B) + C  

Where A, B, and C are real numbers.

Let's see if it does:

10 + (- 5 - 4) = 10 + (-9) = 1

(10 + -(5)) - 4 = 5 - 4 = 1

thiw seems to work, let's se other case:

10 - (5 - 4) = 10 - (1) = 9

now, apply the associative relation

(10 -5) + 4 = 9

Where the sign must change, because we actually have that -(5 - 4) = -1*(5 - 4) so we must distribute the minus sign in the parentheses.

Then, if you take this in mind, you always can use the associative property.

x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x

step-by-step explanation:

last month maria hiked the 5-mile mountain trail a number of times and she hiked the 10-mile canal trail several times. let x represent the number of times she hiked the 5-mile trail, and let y represent the number of times she hiked the 10-mile trail. if she hiked a total of 90 miles, which equation can be used to find the number of times maria hiked each trail? x + y = 90 5x – 10y = 90 90 – 10y = 5x 90 + 10y = 5x