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3 years ago

What's 7n-4=31? What's n=??

Mathematics

2 answers:

levacccp [35]3 years ago

7 0

Answer:

Step-by-step explanation:

solve for n. subtract 4 from 31 and you get 35 then divide 7 by 35 in order to get n which is 5.

sveticcg [70]3 years ago

4 0

Answer:

n=5

Step-by-step explanation:

You might be interested in

The sum of 4 consecutive intergers is 50, what is the first interger in this relationship

Vesnalui [34]

Answer:

x = 11

Step-by-step explanation:

Consecutive means in a row

Let x be the first integer

x+1 is the second

x+2 is the third

x+3 is the 4th

The sum is 50

x+ x+1 + x+2 + x+3 = 50

Combine like terms

4x+6 = 50

Subtract 6 from each side

4x+6-6 = 50-6

4x = 44

Divide each side by 4

4x/4 = 44/4

x = 11

7 0

3 years ago

Question 4 Find the slope and y-intercept in the table. Simplify as needed.

Agata [3.3K]

Answer:

Y - intercept is 1 , slope is 3

4 0

2 years ago

Roberto rowed 20 miles downstream in 2.5 hours. The trip back, however, took him 5 hours. Find the rate that Roberto rows in sti

almond37 [142]

Answer:

Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour

Step-by-step explanation:

Relative Speed

When a body is moving at a constant speed v, the distance traveled in a time t is:

$d=v.t$

When Roberto rows downstream, his speed in still water is added to the speed of the water, making it easier to travel the required distance.

When Roberto rows upstream, his speed in still water is affected by the speed of the water, both are subtracted and the required distance is covered in more time.

Let's call

x = Roberto's rowing speed in still water

y = Speed of the river current

The speed when rowing downstream is x+y, thus the distance traveled is

$d=(x+y).t_1$

Where t1=2.5 hours. Substituting values:

$20=(x+y)*2.5$

Rearranging, we find the downstream equation:

$2.5x+2.5y=20\qquad[1]$

The speed when rowing upstream is x-y, and the distance traveled is

$d=(x-y).t_2$

Where t2=5 hours. Substituting values:

$20=(x-y)*5$

Rearranging, we find the upstream equation:

$5x-5y=20\qquad[2]$

Multiplying [1] by 2:

$5x+5y=40$

Adding this equation to [2]:

$10x=60$

Solving:

$x=60/10=6$

Dividing [2] by 5:

$x-y=4$

Solving for y

$y=x-4=6-4=2$

Thus, Roberto's speed in still water is 6 miles/hour and the river speed is 2 miles/hour

3 0

3 years ago

Tyler baked 702 cookies he sold them in boxes of 18 after selling all of the boxes of cookies for the same amount of each he ear

jenyasd209 [6]

Keywords:

Cookies, boxes, sale, profit, unit cost

For this case we have to bake an amount of 702 cookies, which were distributed in boxes of 18 for sale. Selling each box at the same price earned a profit of 136.50 dollars, you want to know the unit cost of each box of cookies.

Let $"x"$ be the number of boxes of cookies:

So, to know the number of boxes we divide 702 cookies among 18:

$x = \frac {702} {18}\\x = 39$

So, we have Tyler sold 39 boxes of cookies

Now, let $"y"$ be the cost of each box of cookies, to know the unit cost or sale price of the cookie boxes, we divided 136.50 dollars among 39 boxes of cookies, then: