Step-by-step explanation:
Let's say b is the rate of the boat in still water, and c is the rate of the current.
Distance = rate × time
Going upstream:
100 = (b − c) (5)
20 = b − c
Going downstream:
100 = (b + c) (2)
50 = b + c
Solve the system of equations using substitution or elimination.  Using elimination, add the equations together:
70 = 2b
b = 35
c = 15
The boat's speed is 35 km/h, and the current's speed is 15 km/h.
 
        
             
        
        
        
Answer:
80 degrees 
Step-by-step explanation:
Sum of the interior angles of a triangle = 180 
a + 50 + 50 = 180 
a = 80 
 
        
             
        
        
        
Answer:
y = 11.5
Step-by-step explanation:
Given 2 secants from an external point to the circle.
Then the product of the external part and the whole of one secant is equal to the product of the external part and the whole of the other secant, that is
6(6 + y) = 5(5 + 16)
36 + 6y = 5 × 21 = 105 ( subtract 36 from both sides )
6y = 69 ( divide both parts by 6 )
y = 11.5
 
        
             
        
        
        
Answer:
A rational number is a number that can be expressed as a fraction (ratio). This includes whole numbers, square roots that can be solved evenly, negatives, decimals, and repeating decimals that can be solved with a fraction. 
 ↔  .5 ↔  .5
- 5  ↔ 5.0
 ↔ 2.0 ↔ 2.0
- -13  ↔  -13.0
- 0.38462... ( ) )
An irrational number is a number that is NOT rational. It's the complete opposite!
- π  ↔  3.14159
- .13133133...
 ↔  0.86603... ↔  0.86603...
- - ↔  -2.23607... ↔  -2.23607...
 ↔   2.23607... ↔   2.23607...
Hope this helps!!!
 
        
             
        
        
        
The answer is going to be <span>B. 160/8. divide 160/8 to get 20 pages so he reads 20 pages each day and you can check by multiplying 20*8=160</span><span />