Question 204225: respected sir,
plz help me to solve this math prob.
If the numbers x and y are added to set K {5, 1, 6, 4}, the mean will
increase by 50%. What is the value of xsquare + 2xy+ysquare? ?
waiting for yur reply.
thanks u.
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website! If the numbers x and y are added to set K {5, 1, 6, 4}, the mean will
increase by 50%. What is the value of xsquare + 2xy+ysquare? ?
.
Calculate "mean" in original set {5, 1, 6, 4}:
(5+1+6+4)/4
= 16/4
= 4
.
From: "the mean will increase by 50%" we get:
(x+y+5+1+6+4)/6 = 4 + .50(4)
(x+y+5+1+6+4)/6 = 4 + 2
(x+y+5+1+6+4)/6 = 6
(x+y+16)/6 = 6
(x+y+16) = 36
x+y = 20
.
If we simply "square" both sides we get:
(x+y)^2 = 20^2
(x+y)(x+y) = 20^2
Applying FOIL:
x^2 + xy + xy + y^2 = 400
x^2 + 2xy + y^2 = 400
.
Solution: 400
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