Firstly you need to to reduce to a common denominator by multiplYing the whole fraction. This way you have to multiply 4/5 by 2 (both numerator and denominator). so 4/5 = 8/10. And now you have 8/10 and 9/10. You compare only numerators. This way you have 8/10 <9/10. Same goes for 2/3 and 5/8. Only here you need to multiply both fractions. The common denominator here is 24. So you have to multiply 2/3 by 8 and 5/8 by 3. You now have to compare 16/24 and 15/24. 16/24>15/24.
At around 20'000ft. and higher.
<span>To minimize the perimeter you should always have a square.
sqrt(289) = 17
The dimensions should be 17 X 17
To see , try starting at length 1, and gradually increase the length.
The height decreases at a faster rate than the length increases, up until you reach a square.
Or if you want to use algebra, Say the width is 17-x
Then the length is 289/(17-x)
Now, this is bigger than 17+x, as shown here:
289/(17-x) > 17+x
289 > 289 - x^2
which is true.
so the perimeter would be bigger than 2 * (17- x + 17 + x) = 2 * (2 * 17) = 4 * 17
Again, the dimensions should be a square. 17 X 17.</span>
Hello :
<span> y=-6(2.5-x)(x-5.5) = -6(2.5x -13.75 -x² +5.5x)
y = -6(-x²+8x -13.75)
y = 6x²-48x+82.5
note :
if f(x) = ax²+bx +c the vertex is the point : ( -b/2a ; f(-b/2a))
a=6 b=-48 c = 82.5 .......calculate
-b/2a = -(-48)/2(6)= 4
f(4) =6(4)²-48(4)+82.5 =96 - 192 +82.5 = -13.5</span>
