Answer:
7
Step-by-step explanation:
3 * 7 = 21
21 - 7 = 14
7*2 =14
This can be solve by establishing equations.
let x be the miles mrs. storey drove
y be the miles mr storey drovee
the first equation is
y = 3x
second equation
x + y = 3200
then substitute equation 1
x + 3x = 3200
4x = 3200
x = 800 miles mrs storey drove
y = 3x = 2400 miles mr storey drove
Answer: They are inverses of each other
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Explanation:
We'll need to compute h(f(x)) and f(h(x)) to see if we get x each time.

and,

Both composite functions lead to x each time.
The equations h(f(x)) = x and f(h(x)) = x being true means each function is the inverse of the other.
The answer is 9 because 25% of 60 is 15 plus 60% of 60 is 36 so 36+15=51 and 60-51=9
Answer:
length = 60 foot, width = 30 foot
Step-by-step explanation:
Area of rectangular part, A = 1800 ft²
Cost of fencing three sides is $ 6 per foot and cost of one side fencing is $18 per foot.
Let the length of the rectangle is l and the width of the rectangle is W.
Area = Length x width
A = L x W
1800 = L x W ...... (1)
Total cost of fencing, C = 6 x ( L + W + L) + 18 x W
C = 6 (2L + W) + 18 W
C = 12 L + 24 W
Substitute the value of W from equation (1),
in equation (2)


Differentiate both sides with respect to L:

Put it equal to zero for maxima and minima

L = 60 foot
and W = 30 foot
So, the costing is minimum for length = 60 foot and the width = 30 foot.