Question

lcm of 2 numbers x and y is 720 and lcm of 12x and 5y is also 720 find the values of x and y

Answer 1

hye

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lcm of x and y = 720

=> then x and y will be a factor of 720

=>factors of 720

= 1,2,3,4,5,6,8,9,10,12,15,16,18,20,24,30,36,40,45,48,60,72,80,90,120,144,180,240,360,720

=> so x and y must be something from this pattern 

now  12x and 5y 's lcm = is also 720

=> so x = 720/12 = 60

=>y = 720/5 = 144

so x is 60 and y is 144

check lcm of 60 and 144

=>60: 2, 2, 3, 5.

=> 144: 2, 2, 2, 2, 3, 3.

=> LCM: 2, 2, 2, 2, 3, 3, 5.  =  2 x 2 x 2 x 2 x 3 x 3 x 5

= 720

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hope it helps u............

Answer 2

Answer:

144

Step-by-step explanation:

5×12=60 5 × 12 = 60 , so we need only 12 to get the LCM as 720 . And 12x,5y 12 x , 5 y has LCM 720 . Hence, y=144 .