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3 years ago

15

Solving system by substitution

1 answer:

Korvikt [17]3 years ago

6 0

Answer:

The solution of this system is (9, 2).

Step-by-step explanation:

Substitute x - 7 for 'y' in the first equation. We get:

x - 3(x - 7) = 3 Doing this temporarily eliminates the variable 'y'.

Now perform the indicated multiplication, and then combine like terms:

x - 3x + 21 = 3, or

-2x = -18

so that x = 9. Substituting 9 for x in the second equation, we get:

y = 9 - 7, or y = 2.

The solution of this system is (9, 2).

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Jane wishes to bake an apple pie for dessert. The baking instructions say that she should bake the pie in an oven at a constant

Viktor [21]

Answer:

Therefore $k= \frac{ln2 }{18}$ , A=184

Step-by-step explanation:

Given function is

$T(t)=230 -e^{-kt}$

where T(t) is the temperature in °C and t is time in minute and A and k are constants.

She noticed that after 18 minutes the temperature of the pie is 138°C

Putting T(t) =138°C and t= 18 minutes

$138=230 -Ae^{-k\times 18}$

$\Rightarrow -Ae^{-18k}=138-230$

$\Rightarrow Ae^{-18k}=92$ .....(1)

Again after 36 minutes it is 184°C

Putting T(t) =184°C and t= 36 minutes

$184=230-Ae^{-k\times 36}$

$\Rightarrow Ae^{-36k}=230-184$

$\Rightarrow Ae^{-36k}=46$ .......(2)

Dividing (2) by (1)

$\frac{Ae^{-36k}}{Ae^{-18k}}=\frac{46}{92}$

$\Rightarrow e^{-18k}=\frac{46}{92}$

Taking ln both sides

$ln e^{-18k}=ln\frac{46}{92}$

$\Rightarrow -18k =ln (\frac12)$

$\Rightarrow -18k= ln1-ln2$

$\Rightarrow k= \frac{ln2 }{18}$

Putting the value k in equation (1)

$Ae^{-18\frac{ln2}{18}}=92$

$\Rightarrow A e^{ln2^{-1}}=92$

$\Rightarrow A.2^{-1}=92$

$\Rightarrow \frac{A}{2}=92$

$\Rightarrow A= 92 \times 2$

⇒A= 184.

Therefore $k= \frac{ln2 }{18}$ , A=184

7 0

3 years ago

16.63≥m+4.09<br> i need to solve this and i need help

uysha [10]

Hey there mate ;)

As per given question,

$16.63 \geqslant m + 4.09$

$= > 16.63 - 4.09 \geqslant m$

$= > 12.54 \geqslant m$

Therefore, the solution is 12.54 <u>></u><u> </u>m

8 0

3 years ago

Joey Chestnut is trying to break his own record for eating the most whole hot dogs in 10 minutes. He needs to eat more than 72 h

anastassius [24]

The picture below is the answer to your question. I solved it myself when I was doing my homework.

5 0

3 years ago

Read 2 more answers

For a soccer practice, the coach set up four cones, labeled W, X, Y, and Z, to mark the edges of the rectangular field.Suppose t

Ratling [72]

The perimeter of the field is $364$ yards.

The distance between two points $A(x_1, y_1)$ and $B(x_2, y_2)$ is $AB=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}.$

$WX=\sqrt{(-38-(-38))^2+(53-(-53))^2}=106$ units

$XY=\sqrt{(38-(-38))^2+(53-(53))^2}=76$ units

Perimeter $= 2 (l+w)$ , where $l$ is length and $w$ is width.

Perimeter $= 2(106+76)$

$=364$ yards

Learn more about perimeter of rectangle here:

brainly.com/question/2142493?referrer=searchResults

3 0

3 years ago

a bag contains 4 red marbles, 6 blue marbles and 10 yellow marbles. if you reach in the bag and radomly pull out one marble, wha

inna [77]

Answer:

50%

Step-by-step explanation:

4 and 6 make 10.

and there is 10 yellow marbles.

meaning it can be split 50% -50

8 0

4 years ago