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2 years ago

In 3 years time Sarah will be twice as old as Emma was last year .Emma now 11 years how old is Sarah

Mathematics

2 answers:

REY [17]2 years ago

7 0

Answer:

Sarah is 25 years old

Step-by-step explanation:

Andrews [41]2 years ago

3 0

Answer:

Step-by-step explanation:

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Simplify the algebraic expression: 4(3x + y) – 2(x – 5y)

VladimirAG [237]

Answer:

Step-by-step explanation:

First use distribution

4(3x+y)= 12x+4y

and

-2(x-5y)= -2x+10y

combine the 2 answers

10x+14y

3 0

3 years ago

I think of a number and multiply it by 4. I then add 8 and I'm left with an answer of 30. What number did I think of? Form and s

postnew [5]

Answer: number= 5.5; equation: 4x+8=30

Step-by-step explanation:

Take x for the unknown number. Then just follow the words and turn them into mathematical symbols. Easy.

5 0

3 years ago

A calculator is required to obtain the final answer on this question. A solid metal sphere at room temperature 20oC is dropped i

yKpoI14uk [10]

Answer:

T = 47.1875°C

Step-by-step explanation:

Given:

Surrounding temp, Ts = 100°C

Initial Temperature ,T0= 20°C

Increase in temperature = 15°C

Final temperature, T = 20 + 15 = 35°C

Time, t = 9 seconds

Let's take Newton's law of cooling:

$T - Ts = (T_0 - Ts)e^k^t$

We'll solve for k

$35 - 100 = (20 - 100)e^9^k$

$-65 = (-80)e^9^k$

Divide both sides by -5

$13 = (16)e^9^k$

$9k = ln (\frac{13}{16})$

$k = \frac{1}{9} ln (\frac{13}{16})$

$k = -0.02307104053$

Let's now find the temperature of the ball after 18 seconds in boiling water.

Use the Newton's equation again:

$T - Ts = (T_0 - Ts)e^k^t$

$T - 100 = (20 - 100)e^-0.0^2^3^0^7^1^0^4^0^5^3^*^1^8$

$T - 100 = (-80)e^-0.0^2^3^0^7^1^0^4^0^5^3^*^1^8$

$T - 100= -52.8125$

$T = 100 - 52.8125$

T = 47.1875°C

Temperature of the ball after 18 seconds in boiling water is 47.1875°C

5 0

3 years ago

What times 17 -20 equals 180?

grigory [225]

Answer:

Step-by-step explanation:

17-20=3. 60times3 equals 180. So 60

7 0

3 years ago

Use Mental Math to find the value of 15/124 x 230 / 30 ÷ 230 / 124

aksik [14]

it wold be this 0.000032518

6 0

3 years ago

Read 2 more answers