She swims 12 laps on Monday.
Step-by-step explanation:
Total laps = 51 laps
Laps on Saturday = 15 laps 
Let, 
x be the number of laps on Monday, Wednesday and Friday each. 
According to given statement; 
Monday+Wednesday+Friday+Saturday = 51

Dividing both sides by 3

She swims 12 laps on Monday.
Keywords: addition, division
Learn more about division at:
#LearnwithBrainly
 
        
             
        
        
        
Answer:
b is the answer
Step-by-step explanation:
 
        
             
        
        
        
The equation for surface area is: 

. To get r, you must use Pythagorean theorem. r is found to be 45. This means after you plug it in, you get about 
13571.68
 
        
        
        
So for a tangent and a secant, you multiply x^2 (since it’s a tangent you square it) and test that equal to 6(6+12) so now you have x^2=6(6+12). solve for X to get sqrt(108) or 10.4
the equation is — tan^2=outside x whole thing
remember to ADD the entire secant (so add 6 plus 12) don’t multiply them (6x12)
x^2=6(6+12)
x^2=6(18) OR x^2=36+72
x^2=108
x=sqrt(108) OR x=10.4