Michelle would be 54 years old.
72-18=54
Doubling the side-lengths will multiply the area by four.
Proof:
Let the side-lengths of the rectangle by x and y. Clearly, the area will be x*y=xy. The new rectangle will have side-lengths 2x and 2y, and thus area 2x*2y=4xy. 4xy/xy=4 - hence, the new rectangle has four times the area of the old one.
Well for 11, it is an inequality, a > sign or < sign with a little underscore mean either "greater than or equal to" or "less then or equal to" so 30> 12+m (>with an underscore) means 30 is greater than or equal to 12+m
Answer:
(a) 
(b) 
Step-by-step explanation:
Given
Variation: Inverse proportional.
This is represented as:

See attachment for table
Solving (a):
First convert variation to equation

From the table:

So, we have:





Substitute 4 for k in 


Solving (b): x when y = 25.
Substitute 25 for y in 

Cross Multiply

Divide through by 25

Take positive square roots of both sides


Answer:
1 inch=50 miles
Step-by-step explanation:
450÷9=50