If x+y =9 and x-y =5, the value of 4xy is :
If x+y =9 and x-y =5, the value of 4xy is : Correct Answer 56
x + y = 9 x - y = 5 4xy = ( x + y) 2 - ( x - y) 2 = 81 - 25 = 56If x+y =9 and x-y =5, the value of 4xy is : Correct Answer 56
x + y = 9 x - y = 5 4xy = ( x + y) 2 - ( x - y) 2 = 81 - 25 = 56