5(-6 - 12) +4.1= can you help me with this question

300 ml over 15 min is what rate of ml per hour

Mama L [17]

Answer:

1200 ml per hour

Step-by-step explanation:

To compute what rate is 300 ml over 15 mins as a rate of ml per hour, we do a rule of 3, using a variable x as that amount of ml we don't know yet. We should have everything in the same units, so instead of writing 1 hour we write 60 minutes:

$\frac{300~ml}{15~min}=\frac{x~ml}{60~mins}$

Now we solve for x:

$\frac{300~ml}{15~min}\cdot 60~mins=x~ml$

$\frac{18000~ml}{15} =x~ml$

$1200~ml =x~ml$

And so, now that we know the value of x, the rate we wanted to find is

$\frac{1200~ml}{60~mins}$

Which is just 1200 ml per hour.

3 0

3 years ago

(3) In the following circle and rectangle, when AB (the length of segment AB) is 3, BC is 3, and DE is 2.5, find the length of E

dusya [7]

I think that the length of DE is 4. you can add 0.5 to each side of BC in order to find the length of EF since EF starts 0.5 before BC does and therefore also ends 0.5 after BC since the circle is symmetrical.

8 0

3 years ago

John earned three dollars for each lawn he mowed. If he had eight lawns to mow, but forget mow two of them, how much money did h

gayaneshka [121]

If John had to mow 8 lawns, but he forgot to mow 2 lawns, we have to subtract 2 from 8 to see how many lawns he actually mowed.

8-2=6

John mowed 6 lawns!

For each lawn John mowed, he earned 3 dollars. So, we have to multiply the number of lawns he mowed, 6, by the amount of dollars he earned per lawn, 3. Multiplying 6*3 is the same as adding 3+3+3+3+3+3!

6*3=18

John earned $18!

Hope I helped! :)

4 0

3 years ago

Need this answered quick

melisa1 [442]

95.7942857 pie form hope this is right got it off the internet so yeah

7 0

3 years ago

Joanna went school supply shopping. She spent $27.75 on notebooks and pencils. Notebooks cost $2.30 each and pencils cost $1.25

GaryK [48]

Answer:

The answer is A. 5 notebooks and 13 pencils

Step-by-step explanation:

1. Identify your x and y variables.

x - number of notebooks

y - number of pencils

2. Set up two equations to come up with a system of linear equations.

x + y = 18

2.3x + 1.25y = 27.75

3. In order to solve for one of the variables (either x or y), multiply the first equation with the additive inverse (when added together, the answer is zero; one number will be positive while the other number will be negative) of the coefficient of either x or y, so you can eliminate that variable. In this case, I choose the coefficient of y which is 1.25. So, the first equation will look like this:

-1.25(x + y) = 18

-1.25x - 1.25y = -22.50

4. Next, eliminate the y variable and solve for x.

-1.25x - 1.25y = -22.50

2.3 x + 1.25 y = 27.75

__________________

1.05 x = 5.25

1.05 1.05

x = 5 Joanna bought 5 notebooks.

5. Then, solve for y.

5 + y = 18

y = 18 - 5

y = 13 Joanna bought 13 pencils.

If you want to check your work, just plug in 5 and 13 into one of the two original equations. Simplify the equations, and you should get a true statement.

5 + 13 = 18

18 = 18

6 0

4 years ago