Answer:
Let x be odd such that LCM {x,40} = 1400 .
Since 1400 = 23×52×7 , then
x ∈ {5m×7n∣(m,n) ∈ {0,1,2}×{0,1}} .
By testing these values, we find that x = 175 .
For

,

, all the more

, therefore no solution.
For

, we have

. Obviously that' false.
For

both

and

, where

, belong to the range

, then

belong to the range

.
Those ranges don't have a common part, therefore, again, no solution.
So, the equation

doesn't have a solution.
60*80-10*16 if it's regular area and not surface area
Answer:
1200 children and 1500 Adults
Step-by-step explanation:
Suppose x be the children and y be the adults as total people are 2700 that have entered so we can write an equation as
x+y=2700 (Equation 1)
and as per child $1.50 is the cost and $4 for every adult and collectively we have got $7800 so we can write the equation as
1.50x+4y=7800 (Equation 2)
Extracting the value of y from equation 1
Y=2700-x (Equation 3)
Putting the value of y from equation 3 into equation 2
1.50x+4(2700-x)=7800
1.50x+10800-4x=7800
1.50x-4x=7800-10800
-2.5x=-3000
Cancellation of negative signs on both sides
x=3000/2.5
x=1200
Putting the value of x in equation 3 to get the value of y
y=2700-1200
y=1500