3y + 4x = 25, x^2 + y^2 = 25.
Please show me the full steps to solve this using the any simultaneous equation method (substitution, elimination, addition, etc). Thanks.
Please show me the full steps to solve this using the any simultaneous equation method (substitution, elimination, addition, etc). Thanks.
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solve the first equation for y in term of x:
3y + 4x = 25
y = (25-4x)/3
y² = (25-4x)²/9
Substitute for y² in the second equation:
x² + (25-4x)²/9 = 25
9x² + (25-4x)² = 225
Now expand this and you'll have a quadratic equation in x which you can solve for x (2 values probably). Substitute each of those values of x into the first equation and solve for the corresponding value of y.
9x² + 625 - 200x + 16x² = 225
25x² - 200x + 400 = 0
x² - 8x + 16 = 0
(x-4)² = 0
x = 4 (multiplicity 2)
3y + 4(4) = 25
3y = 25-16 = 9
y = 3
Solution (4,3)
The two equations describe a circle of radius 5 centered on the origin, and a line tangent to the circle at the point (4, 3). There is only one distinct solution because the line is tangent at a point instead of intersecting the circle at two points.
And there you have it.
3y + 4x = 25
y = (25-4x)/3
y² = (25-4x)²/9
Substitute for y² in the second equation:
x² + (25-4x)²/9 = 25
9x² + (25-4x)² = 225
Now expand this and you'll have a quadratic equation in x which you can solve for x (2 values probably). Substitute each of those values of x into the first equation and solve for the corresponding value of y.
9x² + 625 - 200x + 16x² = 225
25x² - 200x + 400 = 0
x² - 8x + 16 = 0
(x-4)² = 0
x = 4 (multiplicity 2)
3y + 4(4) = 25
3y = 25-16 = 9
y = 3
Solution (4,3)
The two equations describe a circle of radius 5 centered on the origin, and a line tangent to the circle at the point (4, 3). There is only one distinct solution because the line is tangent at a point instead of intersecting the circle at two points.
And there you have it.
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Solve for x in terms of y, and then plug that value into the equation x^2 + y^2 = 25.
y = (25-4x)/3
x^2 + ((625 - 200x + 16x^2)/9) = 25
Multiply the whole equation by 9:
9x^2 + 625 - 200x + 16x^2 = 225
25x^2 - 200x - 400 = 0
Divide the equation by 25:
x^2 - 8x - 16 = 0
Factor the equation:
(x-4)(x-4) = 0
x = 4
Plug into 3y + 4x = 25 to solve for y.
3y + 4(4) = 25
3y = 25 - 16 = 9
y = 3
So x = 4 and y = 3.
y = (25-4x)/3
x^2 + ((625 - 200x + 16x^2)/9) = 25
Multiply the whole equation by 9:
9x^2 + 625 - 200x + 16x^2 = 225
25x^2 - 200x - 400 = 0
Divide the equation by 25:
x^2 - 8x - 16 = 0
Factor the equation:
(x-4)(x-4) = 0
x = 4
Plug into 3y + 4x = 25 to solve for y.
3y + 4(4) = 25
3y = 25 - 16 = 9
y = 3
So x = 4 and y = 3.
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first equation is 3x+4y=25
now x=(25-4y)/3
Substitute the value of x in the second equation x^2+y^2=25
we will get the value of Y, might be 2 coz this is quadratic equation. then substitute the value of y we will ge the value of x.
now x=(25-4y)/3
Substitute the value of x in the second equation x^2+y^2=25
we will get the value of Y, might be 2 coz this is quadratic equation. then substitute the value of y we will ge the value of x.