Sum of two numbers is 17, and sum of their squares is 185, what is the number
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Sum of two numbers is 17, and sum of their squares is 185, what is the number

[From: ] [author: ] [Date: 11-10-08] [Hit: ]
So we got two pairs: (x = 17, y=4) and (x = 4,x = 13,y = 4,therefore,.......
Suppose that the sum of two numbers is 17, and the sum of their squares is 185. Please help me find the numbers and thank you!

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x + y = 17
x² + y² = 185

y = 17 - x

x² + (17 - x)² = 185
x² + 289 - 34x + x² = 185
2x² - 34x + 104 = 0
2(x² - 17x + 52) = 0
2 (x - 13) (x - 4) = 0
x = 13 or 4

Solve for a respective y.

13 + y = 17
or
4 + y = 17

y = 4 or 13.

IN any case, your two numbers are 4 and 13.

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Sum of two numbers is 17:

x + y = 17


Sum of their squares is 185

x^2 + y^2 = 185

We got the equation system:

x + y = 17
x^2 + y^2 = 185

From first equation: x = 17 - y, put this to second.

(17 - y)^2 + y^2 = 185

289 - 34y + y^2 + y^2 = 185

After solving this quadratic equation you get y = 4 and y = 13.

Now put these to first equation:

x = 17 - y

1) x = 17 - 13 = 4
2) x = 17 - 4 = 13

So we got two pairs: (x = 17, y=4) and (x = 4, y = 17)

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Let one of the number be a
then other number is (17 – a)
a² + (17 – a)² = 185
a² + a² – 34a + 289 = 185
2a² – 34a + 104 = 0
a² – 17a + 52 = 0
(a – 13)(a – 4) = 0
a = 13 or a = 4
other number is 4 or 13
Numbers are 4 and 13
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let n = first number 17-n = second number

n^2 + (17-n)^2 = 185

n^2 +289 - 34n +n^2 = 185

2n^2 -34n +104 = 0

n^2 -17n +52 =0

(n-13)(n-4) = 0

The two numbers are 4 and 13

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x + y = 17

x^2 + y^2 = 185
(x + y)^2 = 185 + 2xy
289 = 185 + 2xy
xy = 52

y = 17 - x

x(17 - x) = 52
17x - x^2 = 52
x^2 - 17x + 52 = 0
(x - 13)(x - 4)
x = 13, x = 4
y = 4, y = 13

therefore, numbers are 4 and 17

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x + y = 17 → y = 17 - x

... x^2 + y^2 = 185
or x^2 + (17-x)^2 = 185
or x^2 + x^2 - 34x + 289 = 185
or 2x^2 - 34x + 104 = 0
or x^2 - 17x + 52 = 0
or (x - 4)(x - 13) = 0
or { x,y } = { 4,13 }

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a+b=17
a^2+b^2=185
the numbers are 13 and 4
1
keywords: and,of,two,squares,sum,what,is,17,185,their,number,numbers,Sum,the,Sum of two numbers is 17, and sum of their squares is 185, what is the number
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