Answer:
Juan went to Walmart to buy notebooks and
highlighters for his classes. Notebooks cost $3
while highlighters cost $4. Juan bought 12 items
and he spent a total of $42. Write a system of
equations that describes this situation
Step-by-step explanation:
3+4÷42
Answer:
12 m
Step-by-step explanation:
This can be solved using the Pythagorean theorem
a^2 = b^2 + c^2
20^2= 16^2 + c^2
400= 256 + c^2
400-256= c^2
144 = c^2
c = √144
c= 12
Answer:
50 dgrees
Step-by-step explanation:
staruight line is 180 so 180 minus 130 is 50
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