7/10x - 5 = 1/2x
7/10x - 1/2x = 5
7/10x - 5/10x = 5
2/10x = 5
x = 5 / (2/10)
x = 5 * 10/2
x = 50/2
x = 25 gallons <===
If you've started pre-calculus, then you know that the derivative of h(t)
is zero where h(t) is maximum.
The derivative is h'(t) = -32 t + 96 .
At the maximum ... h'(t) = 0
32 t = 96 sec
t = 3 sec .
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If you haven't had any calculus yet, then you don't know how to
take a derivative, and you don't know what it's good for anyway.
In that case, the question GIVES you the maximum height.
Just write it in place of h(t), then solve the quadratic equation
and find out what 't' must be at that height.
150 ft = -16 t² + 96 t + 6
Subtract 150ft from each side: -16t² + 96t - 144 = 0 .
Before you attack that, you can divide each side by -16,
making it a lot easier to handle:
t² - 6t + 9 = 0
I'm sure you can run with that equation now and solve it.
The solution is the time after launch when the object reaches 150 ft.
It's 3 seconds.
(Funny how the two widely different methods lead to the same answer.)
The answer is from AL2006
Answer:
(The image is not provided, so i draw an idea of how i supposed that the problem is, the image is at the bottom)
Ok, we have a rectangle of length x by r.
At the extremes of length r, we add two semicircles.
So the perimeter will be equal to:
Two times x, plus the perimeter of the two semicircles (that can be thought as only one circle).
The radius of the semicircles is r, and the perimeter of a circle is:
C = 2*pi*r
where pi = 3.14
Then the perimeter of the track is:
P = 2*x + 2*pi*r.
b) now we want to solve this for x, this means isolating x in one side of the equation.
P - 2*pi*r = 2*x
P/2 - pi*r = x.
c) now we have:
P = 660ft
r = 50ft
then we can replace the values and find x.
x = 660ft/2 - 3.14*50ft = 173ft
Answer:
$25
Step-by-step explanation:
she received$12 five times
12×5=60 ...(1)
she earned$5 two times for yard work
5×2=10....(2)
(1)+(2).... 60+10=70
Bought dog food and ticket
30+15=45
70-45=25
Answer $25 is what she is left with at the end of the month
Since they are similar, you need to find the ratio of similarity (I made up the term, there is probably a correct one that I can’t remember).
If you divide 16/40, you’ll find that that ratio is 2.5. So then you just multiply 16 x 2.5. You’ll get 18.
18 is the length of the top of the trapezoid.
You set 18=2x+4 and solve it algebraically. Subtract 4 from both sides.
14=2x
Divide by 2 and x=7
(You can also check that the ratio is right by 16/18 is the same decimal value as 40/45. You’ll get .88888...)