In this equation, you have to treat the number in the bracket first on the basis of BODMAS
15 - [-3]- 4
Note that when two minuses come together the product is a plus sign.
15 +3 - 4
You have to add before you subract
18 - 4 =14
Therefore, 15- [-3] - 4 = 14.
        
             
        
        
        
270° clockwise rotation & 90° counterclockwise rotation
        
                    
             
        
        
        
Answer:
32 miles 
Step-by-step explanation:
Given data
Let the total distance be x miles
Marks speed= 16miles per hour
Trisha's speed= 12 miles per hour
Trisha has covered 8 miles and has  (x-8) miles to finish line
We know that
Speed= distance/time
time= distance/speed
Hence the time taken for Mark to finish is 
time= x/16---------------1
The time taken for Trisha to finish is
time= (x-8)/12-----------2
equate 1 and 2 above
x/16= (x-8)/12
cross multiply
16(x-8)= 12*x
16x-128= 12x
collect like terms
16x-12x= 128
4x=128
x= 128/4
x= 32 miles
Hence they will meet at exactly 32 miles along the way
 
        
             
        
        
        
8,9,10
how i found this out was if u replace m with 8 it will be 8+7 which is 15 and less then 18
for 9 its 9+7 which is 16 which is less then 18
and for 10 its 10+7 which is 17 which is less then 18
and for 11 its 11+7 is 18 which is equal to 18 so it would not apply to this equation
hope this helps