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3 years ago

Ralph is 3 times as old as Sara. In 6 years, Ralph will be only twice as old as Sara will be then.

1 answer:

5 0

R = 3S

R + 6 = 2 (S+6)

Substitute the first equation in the second one:

(3S) + 6 = 2 (S + 6)

3S + 6 = 2S + 12

S + 6 = 12

R = 18
S = 6

Check:

R is 3 times S now.

In 6 years, R will be (18 + 6) = 24, S will be (6 + 6) = 12.

24 = 2 x 12 yay

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-6h plus 4 - 3plus h equals 11

olga55 [171]

$- 6h + 4 - 3 + h = 11$
So we start by combining like terms;
$- 6h + h = - 5h$
$4 - 3 = 1$
Now we have;
$- 5h + 1 = 11$
We then subtract 1 from both sides;
$- 5h + 1 = 11$
$- 5h = 10$
Then we divide both sides by 5;
$- 5h = 10$
$- 5h \div - 5h = h$
$10 \div - 5h = - 2$
Leaving the final answer to be h = -2

5 0

4 years ago

Si elegimos un día de la semana al azar, ¿qué probabilidad hay de que sea fin de semana (ya sabemos que hay dos días…)?

irga5000 [103]

Answer:

La probabilidad que hay de que sea fin de semana es $\frac{2}{7}$

Step-by-step explanation:

La Probabilidad es la mayor o menor posibilidad de que ocurra un determinado suceso. En otras palabras, la probabilidad establece una relación entre el número de sucesos favorables y el número total de sucesos posibles. Entonces, la probabilidad de un suceso cualquiera A se define como el cociente entre el número de casos favorables (número de casos en los que puede ocurrir o no el suceso A) y el número total de casos posibles. Esta se denomina Ley de Laplace.

$P(A)=\frac{numero de casos favorables}{numero de casos posibles}$

En este caso:

número de casos favorables: 2 (cantidad de días del fin de semana)
número de casos posibles: 7 (cantidad de días totales en la semana)

Reemplazando:

P(A)= $\frac{2}{7}$

La probabilidad que hay de que sea fin de semana es $\frac{2}{7}$

3 0

3 years ago

Evaluate the power: (−3)^4 A. 81 B. -81 C. 243 D. -331

Agata [3.3K]

Answer:

The answer is 81.

Step-by-step explanation:

Since the power of 4 is even, the result will be positive.

${3}^{4}$

Simplify.

$81$

hence, the answer is Option A) 81.

7 0

3 years ago

Read 2 more answers

A line passes through the point, (−8,7) and has a slope of −5/4. Please help...

o-na [289]

Answer:

5x + 4y + 12 = 0

Step-by-step explanation:

Start with the point-slope equation of a straight line: y - k = m(x - h):

Here we are given the point (h, k): (-8, 7) and the slope m = -5/4. Inserting this info into the equation give above, we get: y - 7 = (-5/4)(x + 8).

We must put this equation into "standard form" Ax + By + C = 0.

Multiply all three terms by 4 to remove fractions: 4y - 28 = -5(x + 8), or

4y - 28 + 5x + 40 = 0

Rearranging these terms, we get 5x + 4y + 12 = 0, which is the desired equation in standard form.

8 0

3 years ago

Which numerical setup can be used to calculate the heat energy required to completely melt 100 grams?

BaLLatris [955]

Answer:

Multiplying the mass of ice by the specific latent heat of fusion of ice

Step-by-step explanation:

The heat energy required to completely melt 100 grams can be calculated by multiplying the mass of ice (100g) by the specific latent heat of fusion of ice (336J/g)

5 0

3 years ago