If the arithmetic mean of two numbers is 15 and their geometric mean is 9, find the numbers?
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Let a and b the number
so ,
a+ b /2 = 15
ab =30 ---------------------1
now GM =√ab
=> ✓ ab = 9
ab = 81 ----------------------2
from the equation 1 and 2 we have
(a-b )² =( a+ b) ² -4ab
( a- b )² = 900 - 4× 81
( a-b )² = 900 - 324
( a- b )² = 576
( a- b ) = 24 ------------------(3)
from equation 1 and 3 we get
a + b = 30
a - b = 24
a = 27
b = 3
hope it help you !!!
thanks !!
Ranjan kumar
so ,
a+ b /2 = 15
ab =30 ---------------------1
now GM =√ab
=> ✓ ab = 9
ab = 81 ----------------------2
from the equation 1 and 2 we have
(a-b )² =( a+ b) ² -4ab
( a- b )² = 900 - 4× 81
( a-b )² = 900 - 324
( a- b )² = 576
( a- b ) = 24 ------------------(3)
from equation 1 and 3 we get
a + b = 30
a - b = 24
a = 27
b = 3
hope it help you !!!
thanks !!
Ranjan kumar
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