2. Honestly ur question doesn’t make sense so I just did 1/2 times 4
The GCF, or the largest number that goes into both the numerator and denominator, in this case, is 3
Enjoy your night :)
Answer:
The bottom surface of the glass container will be covered a quarter of the way on March 8th.
Step-by-step explanation:
The bacteria covering the bottom surface of the glass container doubles every day. If the surface is completely covered on March 10th, then one day earlier, on March 9th, half of the surface is covered.
Similarly, if half of the surface is covered on March 9th, then one day earlier, on March 8th, a quarter of the surface is covered.
Therefore, the bottom surface of the glass container will be covered a quarter of the way on March 8th.
Let the speed of river be x km/hr down stream.
Time = Distance / speed
Since river flows downstream, speed of boat down stream = Speed of boat + speed of river = (15 + x).
Since river flows downstream, speed of boat upstream = Speed of boat - speed of river = (15 - x).
Time Upstream - Time Downstream = 75 minutes
Time Upstream = 45 / (15 - x)
Time Downstream = 45 / (15 + x)
75 minutes = 75/60 = 5/4 hours
Time Upstream - Time Downstream = 75 minutes = 5/4 hours
45 / (15 - x) - 45 / (15 + x) = 5/4 Divide both sides by 45
1 / (15 - x) - 1 / (15 + x) = (5/4)*(1/45)
1 / (15 - x) - 1 / (15 + x) = 1/36
((15 + x) - (15 -x)) / (15-x)(15+x) = 1/36
(15 +x - 15 +x) / (15-x)(15+x) = 1/36
2x / (15-x)(15+x) = 1/36
(15-x)(15+x) = 2x*36
(15-x)(15+x) = 72x
225 - x² = 72x
0 = x² + 72x -225
x² + 72x -225 = 0 This is a
quadratic function, use a calculator that can solve the function, by
inputting the function.
x = 3, or -75. Since we are solving for speed, we can not have negative values.
x = 3 is the only valid solution.
Speed of the river = 3 km/hr downstream.
Copyright.
Multiplying is the inverse for division
