kitty<3

1) Si "2.5(de base), 3(de altura), y 7 (de ancho)" son las medidas de todas las cajas (4):

El volumen es:

2.5 * 3 * 7

= $${\mathtt{2.5}}{\mathtt{\,\times\,}}{\mathtt{3}}{\mathtt{\,\times\,}}{\mathtt{7}} = {\frac{{\mathtt{105}}}{{\mathtt{2}}}} = {\mathtt{52.5}}$$

2) Si "2.5(de base), 3(de altura), y 7 (de ancho)" son las medidas de cada caja:

El volumen es:

2.5*3*7  * 4 cajas

= 52.5*4

= $${\mathtt{52.5}}{\mathtt{\,\times\,}}{\mathtt{4}} = {\mathtt{210}}$$

Si es un número negativo, como (-4), usa los paréntesis:

Por ejemplo:

(-4)^2 = 16

(-4)^3 = -64

También puedes se eleva un número a una potencia negativa: 

Por ejemplo:

4^(-2) = 1 / (4)^2

= 1/16

Todos lost variables trabajan con las funciones, pero generalmente utilizamos las variables $${\mathtt{x}}$$ y $${\mathtt{y}}$$.

Por ejemplo: f(x) = x+2

Y:

y = x+2

The Quadratic Formula is used when you have a quadratic equation in the form: $${{\mathtt{ax}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{bx}}{\mathtt{\,\small\textbf+\,}}{\mathtt{c}} = {\mathtt{0}}$$

This page explains the concept more: http://www.purplemath.com/modules/quadform.htm

Oh, deer . . .  Rosala, "5 bucks" is American slang for "5 dollars" :)

Let's use a scenario:

 You have 5 bucks (positive.)

You owe me 5 bucks (negative.) 

But if I said "You do not owe me 5 bucks," the amount of money you would have would be positive again. The double negative makes the statement positive.

Similarly, the double negative with a number makes it positive:

5 is positive.

-5 is negative.

-(-5) would be positive again.

So you start off with 42 houses.

Subtract ((2/3) * 42) first:

$${\mathtt{42}}{\mathtt{\,-\,}}\left({\frac{{\mathtt{2}}}{{\mathtt{3}}}}{\mathtt{\,\times\,}}{\mathtt{42}}\right) = {\mathtt{14}}$$

Now subtract ((3/7) * 14):

$${\mathtt{14}}{\mathtt{\,-\,}}\left({\frac{{\mathtt{3}}}{{\mathtt{7}}}}\right){\mathtt{\,\times\,}}\left({\mathtt{14}}\right) = {\mathtt{8}}$$

Final answer: 8 houses:)

(-46/7) cannot be reduced further because 46 and 7 have no common factors.