Answer: The number of calories increased by 20%.
Step-by-step explanation:
Given : The doctor recommended that Mike increase the number of calories he burns working out from 1,500 to 1,800.
Previous number of calories he used to burn = 1,500
Increase in calories = 1800-1500=300
Now , the percent increase in calories = 

Hence , the number of calories increased by 20%.
#Lets just write x as the nunber you asked
x × 40/100 = 18
x = 18 : 40/100
x = 18 × 100/40
y = 1800/40
y = 45
<h3>
Answer : 45</h3>
Complete Question
The complete question is shown on the first uploaded image
Answer:
a
No singular point due to the exponent in the solution
The interval is 
b
NONE
Step-by-step explanation:
From the question we are told that

The generally solution is mathematically represented as

=> 
integrating both sides

=> 
=> 
=> 
Here 
=> 
From the above equation we see that the domain for x has no singular point the interval is

Also there is no transient term in the general solution obtained because as
there no case where 
9mph because 20 minutes time 3 is one hour so multiply 3 by 3 to get 9
The area of a circle is A = πr^2. We let A1 And A2 the areas of the circles and r1 and r2 the radius of each, respectivley.
A1 + A2 = 80π
Substitute the formula for the area,
π(r1)^2 + π (r2)^2 = 80π
From the statement, we know that r2=2(r1).
<span>π(r1)^2 + π (2 x r1)^2 = 80π
</span>We can cancel π, we will have
5 x (r1)^2 = 80
Thus,
r1 = 4 and r2 = 8