Which of the following expressions are equivalent to (x+y) - (-z)? A. (x+y) - z B. x+ (y+z) C. None of the above

Explanation:

Subtracting a negative is the same as adding. Example: 2-(-3) = 2+3 = 5.

So (x+y)-(-z) is the same as x+y+z. We can group up terms inside parenthesis and it won't change the result. Meaning that x+y+z is the same as any of the following below

We could also swap the order of either x, y or z, and still have the same result.

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.

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