Answer:
A. m^2+7m+10=0
Step-by-step explanation:
This is a problem in pattern matching, and in substituting a variable for a pattern.
(x^2+3)^2 +7x^2 +21 = -10 . . . . . . given
(x^2 +3)^2 +7(x^2 +3) = -10 . . . . . factor the last two terms
m^2 +7m = -10 . . . . . . . . . . . . subsitute m for x^2 +3
m^2 +7m +10 = 0 . . . . . . . . add 10 to both sides; matches A
If x represents the width of the poster (including borders), the area of the finished poster can be written as
.. a = x*(390/(x -10) +8)
.. = 8x +390 +3900/(x -10)
Then the derivative with respect to x is
.. da/dx = 8 -3900/(x -10)^2
This is zero at the minimum area, where
.. x = √(3900/8) +10 ≈ 32.08 . . . . cm
The height is then
.. 390/(x -10) +8 = 8 +2√78 ≈ 25.66 . . . . cm
The poster with the smallest area is 32.08 cm wide by 25.66 cm tall.
_____
In these "border" problems, the smallest area will have the same overall dimension ratio that the borders have. Here, the poster is 10/8 = 1.25 times as wide as it is high.
Answer:
6
Step-by-step explanation:
45/8=5.625
Since there are .625 children left, we need to add another ride to fill in what's left.
Answer:
y=5x+8.50
Step-by-step explanation:
5/4
as 1.00/0.80 = 100/80
and then when you simplify it the answer would be 4/5.
