Given:
The equations of parabolas in the options.
To find:
The steepest parabola.
Solution:
We know that, if a parabola is defined as

Then, the greater absolute value of n, the steeper the parabola.
It can be written as


where
, the smaller absolute value of p, the steeper the parabola.
Now, find the value of |p| for eac equation
For option A, 
For option B, 
For option C, 
For option D, 
Since, the equation is option A has smallest value of |p|, therefore, the equation
represents the steepest parabola.
Hence, the correct option is A.
The formula to find the perimeter of a rectangle is P= 2(l+w). By substituting what we now knowin to the equation:
•42=2(l+(2/5l)). We can have width represented at (2/5l) because it’s now 2/5 of the length. Now add them together to get a single coefficient for l.
•42= 2(7/5l). Multiplying 7/5 by 2.
42= (14/5l). Multiplying both sides by the reciprocal of 14/5, which is 5/14, to get l by itself.
•l= 15.
Now that we now know the value of l, we know that the length is 15m. To find the width of the answer, we then multiply 15 by 2/5, which equals 6. Therefore, the only third option is correct because the length is 15m and the width is 6m.
(m+4)(m+1)
=m^2+5m+4........
5x=3x+20
5x-3x=3x-3x+20
2x=20
2x/2=20/2
X=10 Hope this helped!
-Twix