Answer:
you'll save $18.75, the total being $56.25
Step-by-step explanation:
Multiplication. If you need help just remember PEMDAS.
Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
Answer:
a. 20h + 8
Step-by-step explanation:
-2(-7h-4) + 6h = 14h + 8 + 6h = 20h + 8
Answer:
Step-by-step explanation:
#1 Number of ways picking 2 from 6 = 6C2 = 15
#2 Arranging them in a circle (consider 1 pair AB)
can be done
1,5 (ABBBBB) or (5,1)
2,4 ( AABBBB) or (4,2)
3,3
1,1 (ABABAB)
all up = 7 ways
#3 = product of #1 and #2 = 15x7 = 105
Answer:
2 km/h
Step-by-step explanation:
Let x represent the speed of the river current, t₁ be the time spent rowing against the current and t₂ be the time spent rowing with the current.
Since the speed of the still water = 20 km/h.
The speed of rowing against the current = (20 - x)
The speed of rowing with the current = (20 + x)
We know that velocity = distance / time. Hence time = distance / velocity
t₁ = 36 / (20 - x)
t₂ = 22 / (20 + x)
but t₁ + t₂ = 3 hours
Therefore:
3 = 36 / (20 - x) + 22 / (20 + x)
multiply through by 400 - x²
3(400 - x²) = 36(20 + x) + 22(20 - x)
1200 - 3x² = 720 + 36x + 440 - 22x
3x² + 14x -40 = 0
This gives x = -6.7 or x = 2
x cannot be negative therefore x = 2 km/h
The speed of the river current is 2 km/h
