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3 years ago

What is a counterexample for "subtraction of whole numbers is commutative" ??

1 answer:

6 0

The commutatice property for addition says a+b=b+a
If it was for subtraction, then it would be a-b=b-a
Take a=7 and b=5
7-5 is not equal to 5-7
2 is not equal to -2
So subtraction is not commutative for whole numbers.

Hope this helps :)

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10| x – 4| - 3 > 47

Andrew [12]

Answer:

x < -1 or x > 9

Step-by-step explanation:

$10|x-4|-3>47$

Add 3 to both sides.

$10|x-4|-3+3>47+3$

Simplify.

$10|x-4|>50$

Divide both sides by 10.

$\frac{10|x-4|}{10} >\frac{50}{10}$

Simplify.

$|x-4|>5$

Apply absolute value rule: If $|u|>a,a>0$ then $u < -a$ or $u>a$

$x-4$ or $x-4 >5$

$x-4$

Add 4 to both sides.

$x-4+4$

Simplify.

$x$

$x-4>5$

Add 4 to both sides.

$x-4+4>5+4$

Simplify.

$x>9$

Combine the intervals.

$x$ or $x>9$

8 0

3 years ago

Rhonda drove 51 miles per hour for 5 hours. She then drove 55 miles per hour for x hours. Which expression is equivalent to the

lawyer [7]

The expression equivalent to the total distance Rhonda drove is 51x = 275

Given:

Distance 1:

Number of miles = 51 miles

Number of hours = 5 hours

Distance 2:

Number of miles = 55 miles

Number of hours = x hours

<em>Ratio of miles to number of hours</em> = 51 miles : 5 hours

<em>Ratio of miles to number of hours</em> = 55 miles : x hours

Equate the ratios

51 : 5 = 55 : x

51/5 = 55/x

cross product

51 × x = 5 × 55

51x = 275

x = 275 / 51

x = 5.392156862745098

Approximately,

x = 5.4 hours

Therefore, the number of hours taken to travel 55 miles is 5.4 hours

brainly.com/question/3796978

7 0

3 years ago

Tiana's math test score are 85 and 91 . she has one more test left. in order to earn and a, her average test score must be at le

Harrizon [31]

"at least " means her score has to be more or equal 94
94≤(85+91+x)/3
it looks like correct answer is e.

3 0

3 years ago

Producing a musical costs $88,000 plus $5900 per performance. one sold out performance earns $7500 in revenue. If every performa

yan [13]

X = # of perfomances

y = total amount of money

Income: y = 7500x

Expense: y = 5900x + 88000

Substitution:

7500x = 5900x + 88000

1600x = 88000

x = 55

y = 7500(55) = $412,500

55 performances are needed to break-even.

5 0

3 years ago

Three hens can lay 3 eggs in 3 days.In how many days can 7 hens lay 7 eggs?

Anna71 [15]

Answer: 3 days

Step-by-step explanation: It would take 3 days for seven hens to 7 lay eggs because each hen lays an egg each day.

1 hen/1 egg = 3 days

7 hens/7 days = 14 eggs

7 hens/3 days = 7 eggs

6 0

3 years ago

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