Answer:
![a)220.5\ ft^3\\\\b)\$2,425.5](https://tex.z-dn.net/?f=a%29220.5%5C%20ft%5E3%5C%5C%5C%5Cb%29%5C%242%2C425.5)
Step-by-step explanation:
a) The volume of a rectangular prism can be calculated by multiplying its dimensions.
In this case, you know the rectangular solid has 21 feet long, 14 feet wide, and 9 inches deep.
Since
, then its depth in feet is:
![depth=\frac{(9\ in)(1\ ft)}{12\ in}=\frac{3}{4}\ ft](https://tex.z-dn.net/?f=depth%3D%5Cfrac%7B%289%5C%20in%29%281%5C%20ft%29%7D%7B12%5C%20in%7D%3D%5Cfrac%7B3%7D%7B4%7D%5C%20ft)
Therefore, its volume is:
![V=(21\ ft)(14\ ft)(\frac{3}{4}\ ft)\\\\V=220.5\ ft^3](https://tex.z-dn.net/?f=V%3D%2821%5C%20ft%29%2814%5C%20ft%29%28%5Cfrac%7B3%7D%7B4%7D%5C%20ft%29%5C%5C%5C%5CV%3D220.5%5C%20ft%5E3)
b) Knowing that each cubic foot of mulch costs $11, you can calculate the total cost of the mulch the contractor needs to buy, multiplying the volume by the $11.
Then, you get:
![Total\ cost=(220.5)(\$11)=\$2,425.5](https://tex.z-dn.net/?f=Total%5C%20cost%3D%28220.5%29%28%5C%2411%29%3D%5C%242%2C425.5)
Resolviendo un sistema de ecuaciones, vemos que se venden 6 libros de secundaria 4 y 6 libros de secundaria 1.
<h3>
¿Como escribir un sistema de ecuaciones?</h3>
Primero definimos dos variables:
- x = numero de libros de secundaria 4 vendidos.
- k = número de libros de secundaria 1 vendidos.
Sabemos que se venden 12 libros en total, entonces:
x + k = 12
Tambien sabemos que se recauda un total de $82, entonces:
x*$8 + k*$6 = $82
Entonces tenemos dos ecuaciones.
a) Usando la primer ecuacion, podemos aislar x para tener:
x = 12 - k
b) Ahora podemos reemplazar eso en la otra ecuación para solucionar el sistema.
(12 - k)*$8 + k*$6 = $82
$96 - $2*x = $82
$2*x = $12
x = $12/$2 = 6
Es decir se venden 6 libros de secundaria 4, y como se venden 12 libros en total, los otros 6 libros vendidos son de secundaria 1.
Si quieres aprender más sobre sistemas de ecuaciones:
brainly.com/question/13729904
#SPJ1
Answer:
(x + 3)(x + 4) = 110
or x² + 7x + 12 = 110
Step-by-step explanation:
Answer:
339.2hm
Step-by-step explanation:
I am not the mathematician