Answer:
<em>4.52secs</em>
Step-by-step explanation:
Given the height of a falling object expressed as;
d=3t+5t^2
If the object travel 84 feet, we are to find the time t it takes to travel. On substituting;
84 = 3t+5t^2
3t+5t^2 - 84 = 0
t = -5±√25-4(3)(-84)/2(3)
t = -5±√25+1008/6
t = -5±32.14/6
t = -5+32.14/6
t = 27.14/6
<em>t = 4.52 secs</em>
<em>Hence it will take 4.52secs for the object to travel 84feet</em>
Answer:
Therefore x=9
Step-by-step explanation:
Give that,
log x+ log (x-3) = log 54
log x(x-3) =log 54 [
]
x(x-3) = 54
Now expand the above equation to get a quadratic equation
x²-3x=54
⇒x²-9x+6x-54=0
⇒x(x-9)+6(x-9)=0
⇒(x-9)(x+6)=0
⇒x-9=0 or, x+6=0
⇒x=9,-6
Now putting x= -6 in the given expression,
log(-6)+log(-6-9)=log 54.
Since log (-6) does not exist.
Therefore x=9
Answer:
-78.12
Step-by-step explanation: