if x+y = 7/2 and xy = 5/2 find x -y ( solve using algebra identities)
Answers
Answered by
110
(x-y)^2=x^2 + y^2 -2xy........1
(x+y)^2=x^2 + y^2 + 2xy
49/4 - 5=x^2 + y^2
29/4=x^2 + y^2
put in 1
u got
(x-y)^2=29/4 - 5=9/4
x-y= 3/2
please mark it as a brainliest answer
(x+y)^2=x^2 + y^2 + 2xy
49/4 - 5=x^2 + y^2
29/4=x^2 + y^2
put in 1
u got
(x-y)^2=29/4 - 5=9/4
x-y= 3/2
please mark it as a brainliest answer
Answered by
29
x+y=7/2. First equation
xy=5/2
y=5/2x
Substitute in 1
x+5/2x=7/2
2x^2+5=7x
2x^2-7x+5=0
2x^2-2x-5x+5=0
2x(x-1) -5(x-1)=0
x= 5/2 or 1
y =1or 5/2
xy=5/2
y=5/2x
Substitute in 1
x+5/2x=7/2
2x^2+5=7x
2x^2-7x+5=0
2x^2-2x-5x+5=0
2x(x-1) -5(x-1)=0
x= 5/2 or 1
y =1or 5/2
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