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3 years ago

Evaluate 5r - 8.35s when r = 12 and s = 4.

Mathematics

2 answers:

Dvinal [7]3 years ago

6 0

Answer:

It should be 26.6

Step-by-step explanation:

wel3 years ago

4 0

Answer:

26.6

Step-by-step explanation:

5r=60

8.35s=33.4

60-33.4=26.6

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Help please I don't know what to do plz just send the answers because I'm tired and I cba to do calculations

Lyrx [107]

Answer is A
Just make sure you do know how to do them :)

4 0

3 years ago

Solve the following differential equation: (1− 5 y +x) dy/dx +y= 5/x −1 . C=

Ganezh [65]

Answer:

$y(1+x)+x-5\ln xy=C$

Step-by-step explanation:

Consider the given differential equation is

$(1-\frac{5}{y}+x)\frac{dy}{dx}+y=\frac{5}{x}-1$

$(1-\frac{5}{y}+x)\frac{dy}{dx}=\frac{5}{x}-1-y$

$(1-\frac{5}{y}+x)dy=(\frac{5}{x}-1-y)dx$

Taking all variables on right sides.

$(1-\frac{5}{y}+x)dy-(\frac{5}{x}-1-y)dx=0$

$(-\frac{5}{x}+1+y)dx+(1-\frac{5}{y}+x)dy=0$

Let as assume,

$M=-\frac{5}{x}+1+y$ and $N=1-\frac{5}{y}+x$

Find partial derivatives $\frac{\partial M}{\partial y}$ and $\frac{\partial N}{\partial x}$

$\frac{\partial M}{\partial y}=1$ and $\frac{\partial N}{\partial x}=1$

Since $\frac{\partial M}{\partial y}=\frac{\partial N}{\partial x}$ , therefore the given differential equation is exact.

The solution of the exact differential equation is

$\int Mdx+\int N(\text{without x)}dy=C$

$\int (-\frac{5}{x}+1+y)dx+\int (1-\frac{5}{y})dy=C$

$yx-5\ln x+x+y-5\ln y=C$

$y+x+xy-5\ln x-5\ln y=C$

$y(1+x)+x-5(\ln x+\ln y)=C$

$y(1+x)+x-5\ln xy=C$

7 0

3 years ago

An engineer is planning a new water pipe installation. The circular pipe has a diameter of d=20\text{ cm}d=20 cmd, equals, 20, s

aivan3 [116]

Answer: The answer is 314.28 cm² (approx.).

Step-by-step explanation: Given that an engineer is going to install a new water pipe. The diameter of this circular pipe is, d = 20 cm.

We need to find the area 'A' of the circular cross-section of the pipe.

Given, diameter of the circular section is

$\textup{d}=20~\textup{cm}.$

So, the radius of the circular cross-section will be

$\textup{r}=\dfrac{\textup{d}}{2}=\dfrac{20}{2}=10~\textup{cm}.$

Therefore, cross-sectional area of the pipe is

$\textup{A}=\pi \textup{r}^2=\dfrac{22}{7}(10)^2=\dfrac{2200}{7}=314\dfrac{2}{7}=314.28~.~.~.~\textup{cm}^2.$

Thus, the answer is 314.28 cm² (approx.).

4 0

3 years ago

Solve |p + 2| = 10Solve |p + 2| = 10 {-12} {-8, 8} {-12, 8}

valentinak56 [21]

By definition, we have

$|p+2| = \begin{cases} p+2 &\text{ if } p+2 \geq 0 \\-p-2 &\text{ if } p+2 < 0 \end{cases}$

So, we have to solve two different equations, depending of the possible range for the variable. We have to remember about these ranges when we decide to accept or discard the solutions:

Suppose that $p+2\geq 0 \iff p \geq -2$

In this case, the absolute value doesn't do anything: the equation is

$p+2 = 10 \iff p = 10-2 = 8$

We are supposing $p \geq -2$ , so we can accept this solution.

Now, suppose that $p+2 < 0 \iff p < -2$ . Now the sign of the expression is flipped by the absolute value, and the equation becomes

$-p-2 = 10 \iff -p = 12 \iff p = -12$

Again, the solution is coherent with the assumption, so we can accept this value as well.

3 0

3 years ago

Plzzz help i am ineeeddeddeedeededed of it!!!

Vikentia [17]

Sallys statement is always true
for example:
-6 + 2 = -4
but if I turn it around
2 - 6 = -4
same answer

-6 -6 = -12
swap around -6 - 6 = 12
same answer

again -3 + 6 = 3
and 6 - 3 = 3

6 0

4 years ago