If x+y=15 and xy=56 so x-y=?
Answers
Answered by
4
x + y =15
xy= 56
(x+y)^2 =x^2 +y^2 +2xy
225 = x^2 + y^2 + 112
225 -112 =x^2 +y^2
(x-y)^2 = 113- 112 =1
x - y = 1
xy= 56
(x+y)^2 =x^2 +y^2 +2xy
225 = x^2 + y^2 + 112
225 -112 =x^2 +y^2
(x-y)^2 = 113- 112 =1
x - y = 1
Gayanshukumar:
Answer is 3
Wrong
No
Which class you read
Mandeep ... The square of 15 is 225
not 256
edit it
ok
Answered by
7
Hey mate.......^_^
Here's ur ans. ⤵
➡ x + y = 15
x = 15 - y
Substituting the value of x in 2nd equation
(15 - y ) y =56
15y - y^2 = 56
y^2 - 15y + 56 = 0
y^2 - 8y- 7y + 56
y(y - 8) - 7 ( y - 8)
y = 7
y = 8
Therefore , x = 15 - 8 = 7
15 - 7 = 8
➡ x - y = 7-8 = -1
x-y = 8-7 = 1
✌Hope it helps
Here's ur ans. ⤵
➡ x + y = 15
x = 15 - y
Substituting the value of x in 2nd equation
(15 - y ) y =56
15y - y^2 = 56
y^2 - 15y + 56 = 0
y^2 - 8y- 7y + 56
y(y - 8) - 7 ( y - 8)
y = 7
y = 8
Therefore , x = 15 - 8 = 7
15 - 7 = 8
➡ x - y = 7-8 = -1
x-y = 8-7 = 1
✌Hope it helps
Answer is 3
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