<span>a plane figure with four straight sides and four right angles, especially one with unequal adjacent sides, in contrast to a square.</span>
Answer:
xy(y - x)(y + x)
Step-by-step explanation:
take out a common factor xy from both terms
= xy(y² - x²)
y² - x² is a difference of squares and factors in general as (y - x)(y + x)
Hence
xy³ - x³y = xy(x - y)(x + y)
Let d = number of dimes, q = number of quarters
<span>Sally has 20 coins in her piggy bank, so </span>
<span>d + q = 20 </span>
<span>The total amount of money is $3.05. </span>
<span>Use the value of each coin multiplied by its number to get total value </span>
<span>.10d + .25q = 3.05 </span>
<span>multiply everything by 100 to clear the decimal places </span>
<span>10d + 25q = 305 and </span>
<span>d + q = 20 </span>
<span>solve the second equation above in terms of either d or q - lets do d </span>
<span>d = 20 - q </span>
<span>sub that into the first equation </span>
<span>10d + 25q = 305 </span>
<span>10(20 - q) + 25q = 305 </span>
<span>200 - 10q + 25q = 305 </span>
<span>15q = 105 </span>
<span>q = 105/15 = 7 </span>
<span>and from above </span>
<span>d = 20 - q = 20 - 7 = 13 </span>
<span>so, there are 13 dimes and 7 quarters </span>
<span>verify with orig problem </span>
<span>13 + 7 = 20, OK, and $1.30 + $1.75 = $3.05
</span>
Answer:
Un batido de proteínas cuesta $ 5,25.
Step-by-step explanation:
El sistema de ecuaciones descrito al final del enunciado coincide con lo descrito al comienzo del mismo, de modo que podemos concentraron casi exclusivamente en la resolución del sistema en cuestión, la cual se describe a continuación:
Este es el sistema a resolver:
(1)
(2)
Donde 
es el coste de un batido de fresa y 
corresponde al coste de un batido de proteínas:
1) Despejamos en (1):
2) Eliminamos en (2):
3) Simplificamos y despejamos :
Un batido de proteínas cuesta $ 5,25.
Step 2 she should add 4 not subtract
