Answer:
Step-by-step explanation:
1st boat:
Parabola equation:
The x-coordinate of the vertex:
Equation:
The y-coordinate of the vertex:
Parabola passes through the point (-8,1), so
Solve:
Parabola equation:
2nd boat:
Parabola equation:
The x-coordinate of the vertex:
Equation:
The y-coordinate of the vertex:
Parabola passes through the point (-8,1), so
Solve:
Parabola equation:
System of two equations:
Answer:
58.33 lbs.
Step-by-step explanation:
There are already 25 lbs of alloy of copper
Of this 25 lbs, 20% is pure i.e. copper content = 25(0.5) = 5lbs.
Now available is
Copper Other metals
5 lbs 20 lbs
Let x lb of 30% copper is added.
Then new alloy will have 5+0.3x lb copper in total of 25+x lbs
Percentage pure =
Simplify to get
Hence answer is 58.33 lbs should be added.
Answer:
14 days
Step-by-step explanation:
Amount earned by gardener for each day worked = $60
Amount paid by gardener for each day when absent = $15
Total number of days = 20
Let the total number of days when the gardener was working = x
Then he was absent for (20 - x) days.
Total amount earned during this period = $750
Then,
=>
=> \[75x = 1050\]
=> x = 14
So the gardener worked for 14 days out of 20.