xy=1 2x+y=8 by equality
Question
Answer:
To solve this system of equations:
1. xy = 1
2. 2x + y = 8
You can use the method of substitution. First, let's solve one of the equations for one of the variables and then substitute it into the other equation:
From equation 1, we can solve for y:
xy = 1
y = 1/x
Now, substitute this expression for y into equation 2:
2x + (1/x) = 8
To get rid of the fraction, multiply both sides of the equation by x:
2x^2 + 1 = 8x
Rearrange the terms:
2x^2 - 8x + 1 = 0
Now, you have a quadratic equation. You can solve it using the quadratic formula:
x = (-b Β± β(b^2 - 4ac)) / (2a)
In this case, a = 2, b = -8, and c = 1. Plug these values into the quadratic formula:
x = (-(-8) Β± β((-8)^2 - 4(2)(1))) / (2(2))
x = (8 Β± β(64 - 8)) / 4
x = (8 Β± β56) / 4
Now, simplify:
x = (8 Β± 2β14) / 4
x = (2(4 Β± β14)) / 4
x = (4 Β± β14) / 2
Now, you have two possible values for x:
1. x = (4 + β14) / 2
2. x = (4 - β14) / 2
Now, substitute these values back into the equation y = 1/x to find the corresponding values of y:
1. If x = (4 + β14) / 2, then y = 1 / [(4 + β14) / 2] = 2 / (4 + β14)
2. If x = (4 - β14) / 2, then y = 1 / [(4 - β14) / 2] = 2 / (4 - β14)
So, there are two sets of solutions for this system of equations:
1. (x, y) = ((4 + β14) / 2, 2 / (4 + β14))
2. (x, y) = ((4 - β14) / 2, 2 / (4 - β14))
solved
general
11 months ago
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