IDNStudy.com, ang platform na nag-uugnay ng mga tanong sa mga solusyon. Sumali sa aming platform ng tanong at sagot upang makatanggap ng mabilis at eksaktong tugon mula sa mga propesyonal sa iba't ibang larangan.
Sagot :
We let the time that Jane takes to finish the job be x, so for Mary it is x+3.
This makes the rates of Jane and Mary be 1/x and 1/(x+3) respectively.
1/[1/x + 1/(x+3)] = 2
1 = 2/x + 2/(x+3)
1 = (4x+6)/(x²+3x)
x²+3x = 4x+6
x²-x-6 = 0
Method 1: Guess and Check
We look for two number with a product of 6 and an absolute difference of 1
6 - 1 = 5 X
3 - 2 = 1 √
So: (x-3)(x+2)=0
Therefore x is either 3 or -2 but we cannot have a negative time so we only consider 3. Therefore Mary's time is 6 hours. It takes her 6 hours to do it alone.
Method 2: Quadratic Formula
x = 1 ± √(1+24) = 1 ± 5 = -2 or 3
2 2
Again, we cannot have a negative value. So Jane's time is 3 hours and Mary's is 6 hours. So the answer is 6 hours.
This makes the rates of Jane and Mary be 1/x and 1/(x+3) respectively.
1/[1/x + 1/(x+3)] = 2
1 = 2/x + 2/(x+3)
1 = (4x+6)/(x²+3x)
x²+3x = 4x+6
x²-x-6 = 0
Method 1: Guess and Check
We look for two number with a product of 6 and an absolute difference of 1
6 - 1 = 5 X
3 - 2 = 1 √
So: (x-3)(x+2)=0
Therefore x is either 3 or -2 but we cannot have a negative time so we only consider 3. Therefore Mary's time is 6 hours. It takes her 6 hours to do it alone.
Method 2: Quadratic Formula
x = 1 ± √(1+24) = 1 ± 5 = -2 or 3
2 2
Again, we cannot have a negative value. So Jane's time is 3 hours and Mary's is 6 hours. So the answer is 6 hours.
Natutuwa kami na ikaw ay bahagi ng aming komunidad. Patuloy na magtanong at magbahagi ng iyong mga ideya. Sama-sama tayong magpapaunlad ng kaalaman para sa lahat. Para sa mabilis at maasahang mga sagot, bisitahin ang IDNStudy.com. Nandito kami upang tumulong sa iyo.