9514 1404 393
Answer:
1. 5 seconds
2. 4.5 seconds
Step-by-step explanation:
Both of these questions can be solved the same way. Each quadratic gives height as a function of time. You're interested in the time at which the height is zero. Factor the quadratic and find the positive value of x that makes the relevant factor be zero.
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1) y = -15x(x -5)
x = 5 makes the second factor zero
The golf ball is in the air 5 seconds.
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2) y = -12x(x -4.5)
x = 4.5 makes the second factor zero
The football is in the air for 4.5 seconds.
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<em>Additional comment</em>
The "zero product rule" tells you a product will be zero if and only if one or more of the factors is zero. When a factored quadratic (or any other polynomial) is zero, one of the factors must be zero. If the factor is of the form (ax+b), then the corresponding solution is ...
ax+b = 0 ⇒ ax = -b ⇒ x = -b/a
That is, once you have the factored form, you can write the solutions "by inspection."
Answer:
El lado del cuadrado inicial es 17 m.
Step-by-step explanation:
El área de un rectángulo se calcula a partir de los dos lados diferentes. Siendo a y b el valor de ambos lados, el área de la figura es el producto de los dos lados contiguos del rectángulo.
A los lados de un cuadrado se le aumenta en 3 y 5 m respectivamente la superficie del nuevo rectángulo es 440 m². Siendo x el lado del cuadrado inicial, entonces el área del rectángulo se puede expresar como:
(x+3)*(x+5)= 440 m²
Resolviendo:
x*x + 5*x + 3*X + 3*5= 440
x² + 8*x + 15=440
x² + 8*x + 15 -440= 0
x² + 8*x -425= 0
Una función cuadrática de la forma a*x² + b*x + c= 0 se puede resolver mediante la expresión:
En este caso, a=1, b=8 y c=425. Reemplazando:
Resolviendo:
y
Como las longitudes no pueden ser negativas, <u><em>el lado del cuadrado inicial es 17 m.</em></u>
Answer:
m=24
Step-by-step explanation:
First, we can combine like terms:
m/(5-2)=8
m/3=8
Now, we need to get m by itself. To do this, multiply by 3:
m/3*3=8*3
m=24
You should put a picture of the problem so I can help
Answer:
3-2 credits + 20% = 9
Step-by-step explanation:
