All categories

3 years ago

Helppp me please i’m going to fail

Mathematics

1 answer:

Debora [2.8K]3 years ago

4 0

Multiple the top equation by 2 and rearrange so that -7 is equal to the others.
-10x+2y=-14
-3x-2y=-12
——————-
-13x=-26
Divide both by -13
x=2

You might be interested in

Could you solve x. If possible could you be fast with it 2x+3=5x+3–3x

Ber [7]

Answer:

3 = 3 (infinitely many solutions)

Step-by-step explanation:

4 0

3 years ago

What is 7285 divided by 4

serg [7]

Answer:

1821.25

Step-by-step explanation:

$\frac{7285}{4}$ = 1821.25

5 0

3 years ago

To find the sum of 4 and -5.

Katen [24]

Answer:

-1

Step-by-step explanation:

-5 + 4 = 1

5 0

3 years ago

A large tank is filled to capacity with 300 gallons of pure water. brine containing 5 pounds of salt per gallon is pumped into t

Licemer1 [7]

If $A(t)$ is the amount of salt in the tank at time $t$ , then the rate at which this amount changes over time is given by the ODE

$A'(t)=\dfrac{3\text{ gal}}{1\text{ min}}\cdot\dfrac{5\text{ lb}}{1\text{ gal}}-\dfrac{3\text{ gal}}{1\text{ min}}\cdot\dfrac{A(t)\text{ lb}}{300+(3-3)t\text{ gal}}$

$A'(t)+\dfrac1{100}A(t)=15$

We're told that the tank initially starts with no salt in the water, so $A(0)=0$ .

Multiply both sides by an integrating factor, $e^{t/100}$ :

$e^{t/100}A'(t)+\dfrac1{100}e^{t/100}A(t)=15e^{t/100}$
$\left(e^{t/100}A(t)\right)'=15e^{t/100}$
$e^{t/100}A(t)=1500e^{t/100}+C$
$A(t)=1500+Ce^{-t/100}$

Since $A(0)=0$ , we have

$0=1500+C\implies C=-1500$

so that the amount of salt in the tank over time is given by

$A(t)=1500(1-e^{-t/100})$

After 10 minutes, the amount of salt in the tank is

$A(10)=1500(1-e^{-1/10})\approx142.74\text{ lb}$

8 0

3 years ago

There is a language with 12 distinct letters. How many words that are less than four letters long can possibly be formed? (Assum

allochka39001 [22]

Answer:

1884

Step-by-step explanation:

1)If you hear the condition "less than four letters" it means that each word can consist of 3,2 or 1 letter. Firstly, consider the easiest situation with the word from one letter. There are 12 letters, so there are 12 words from one letter.

Then the words from two letters. The first letter of such a word can be chosen in 12 means(because 12 letters are available), then the second letter can be chosen in 12 means too. 12*12=144 words with 2 letters. (Multiplying, not adding, because each two words form one combination).

Then for the words from three letters, use the same rule, 12 means for the first letter, 12 means for the second letter, 12 means for the third letter. 12*12*12=1728 words.

Having particular words from 1,2,3 letters add them to get total quantity of words: 12+144+1728=1884words,that is the answer.

8 0

3 years ago