84o students would be expected to play outdoor games for at least three hours every week.
The sample showed that 70% students played outdoor games for at least three hours every week. 70% of 1,200 is 840.
Answer:
im in the same question as you bro
Step-by-step explanation:
Answer:
5(4 + 3c) - 12 = 15c + 8
Step-by-step explanation:
1st step, expand it to make it a little easier to solve, 20 + 15c - 12
2nd step, subtract, 20 - 12 = 8
3rd step simplify, 15c + 8
Ahh, this question goes all the way back to my year 9 test a couple years ago; which I got wrong back then - I now know how
Firstly we find the expression for the area (using x as the walk way):
>50x * 2 (the left and right)
>20x * 2 (the top and bottom)
>4 * x^2 (the corners)
Add them all together , Area = 140x + 4x^2
Now we place the deck's area, <u>456</u> into the expression
456 = 140x + 4x^2
Solve for x
I'm a bit rusty on this i'm afraid, but I believe the only way to solve this is to factorise it
0 = 4x^2 + 140x - 456
0 = 4(x+38)(x-3) <
<u>x must = -38 or = +3 (the numbers inside the brackets inverted)</u>
x must = +3 as it's logical, you can't have a negative width
The walkway is 3 feet wide, we can put this into our expression to double check this,
<em>456 = 140*(3) + 4(3)^2</em>
<em>456 = 420 + 4*9</em>
<em>456 = 420 + 36</em>
<em>456 = 456
</em>Yes, 3 feet wide is correct.
*Note, I tried to keep this simple, please let me know if I didn't go into enough detail anywhere