Answer: x = (sqrt(7) + 2)/3 and
x = ( – sqrt(7) + 2)/3
Explanation:
3x^2 - 4x - 1 = 0
Divide both sides by 3:
3x^2/3 - 4/3x - 1/3 = 0/3
x^2 - 4/3x - 1/3 = 0
x^2 - 4/3x = 1/3
x^2 - 4/3x + (2/3)^2 = 1/3 + (2/3)^2
(x - 2/3)^2 = 1/3 + 4/9
(x - 2/3)^2 = 7/9
Sqrt both sides:
x - 2/3 = sqrt (7/9)
x - 2/3 = |sqrt(7)/3|
Set x -2/3 = sqrt(7)/3
=> x = (sqrt(7) + 2)/3
Set x - 2/3 = - sqrt(7)/3
=> x = ( - sqrt(7) + 2)/3
16x^2 + 25y^2 + 160x - 200y + 400 = 0 Rearrange and regroup.
(16x^2 + 160x) + (25y^2 - 200y ) = 0-400. Group the xs together and the ys together.
16(X^2 + 10x) + 25(y^2-8y) = -400. Factorising.
We are going to use completing the square method.
Coefficient of x in the first expression = 10.
Half of it = 1/2 * 10 = 5. (Note this value)
Square it = 5^2 = 25. (Note this value)
Coefficient of y in the second expression = -8.
Half of it = 1/2 * -8 = -4. (Note this value)
Square it = (-4)^2 = 16. (Note this value)
We are going to carry out a manipulation of completing the square with the values
25 and 16. By adding and substracting it.
16(X^2 + 10x) + 25(y^2-8y) = -400
16(X^2 + 10x + 25 -25) + 25(y^2-8y + 16 -16) = -400
Note that +25 - 25 = 0. +16 -16 = 0. So the equation is not altered.
16(X^2 + 10x + 25) -16(25) + 25(y^2-8y + 16) -25(16) = -400
16(X^2 + 10x + 25) + 25(y^2-8y + 16) = -400 +16(25) + 25(16) Transferring the terms -16(25) and -25(16)
to other side of equation. And 16*25 = 400
16(X^2 + 10x + 25) + 25(y^2-8y + 16) = 25(16)
16(X^2 + 10x + 25) + 25(y^2-8y + 16) = 400
We now complete the square by using the value when coefficient was halved.
16(x-5)^2 + 25(y-4)^2 = 400
Divide both sides of the equation by 400
(16(x-5)^2)/400 + (25(y-4)^2)/400 = 400/400 Note also that, 16*25 = 400.
((x-5)^2)/25 + ((y-4)^2)/16 = 1
((x-5)^2)/(5^2) + ((y-4)^2)/(4^2) = 1
Comparing to the general format of an ellipse.
((x-h)^2)/(a^2) + ((y-k)^2)/(b^2) = 1
Coordinates of the center = (h,k).
Comparing with above (x-5) = (x - h) , h = 5.
Comparing with above (y-k) = (y - k) , k = 4.
Therefore center = (h,k) = (5,4).
Sorry the answer came a little late. Cheers.
Answer:
1 3/20
Step-by-step explanation:
2/5 = 8/20
3/4 = 15/20
8/20+15/20 = 13/20
Answer:
X>3
Step-by-step explanation:
X+9<4X
x-x+9<4x-x
9<3x
3<x
The length of QJ is 4√20 units if the QJ = 4×PQ after using the intersecting chords theorem.
<h3>What is a circle?</h3>
It is described as a set of points, where each point is at the same distance from a fixed point (called the center of a circle)
By intersecting chords theorem:
QM×QL = QJ×PQ
10×8 = QJ(QJ/4)
4×80 = QJ²
QJ = 4√20 units
Thus, the length of QJ is 4√20 units if the QJ = 4×PQ after using the intersecting chords theorem.
Learn more about circle here:
brainly.com/question/11833983
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