To solve the equation 81 y 2 − 4 = ( x − 2 ) ( x + 3 ) + 6 ( x − 1 ) 2 81y^2 - 4 = (x - 2)(x + 3) + 6(x - 1)^2 81 y 2 − 4 = ( x − 2 ) ( x + 3 ) + 6 ( x − 1 ) 2 , we'll begin by expanding the right-hand side and then simplify the equation:
Step 1: Expand the right-hand side:
81 y 2 − 4 = ( x − 2 ) ( x + 3 ) + 6 ( x − 1 ) 2 81y^2 - 4 = (x - 2)(x + 3) + 6(x - 1)^2 81 y 2 − 4 = ( x − 2 ) ( x + 3 ) + 6 ( x − 1 ) 2
Step 2: Perform the multiplication on the right-hand side:
81 y 2 − 4 = ( x 2 − 2 x + 3 x − 6 ) + 6 ( x 2 − 2 x + 1 ) 81y^2 - 4 = (x^2 - 2x + 3x - 6) + 6(x^2 - 2x + 1) 81 y 2 − 4 = ( x 2 − 2 x + 3 x − 6 ) + 6 ( x 2 − 2 x + 1 )
Step 3: Combine like terms:
81 y 2 − 4 = ( x 2 + x − 6 ) + 6 x 2 − 12 x + 6 81y^2 - 4 = (x^2 + x - 6) + 6x^2 - 12x + 6 81 y 2 − 4 = ( x 2 + x − 6 ) + 6 x 2 − 12 x + 6
Step 4: Combine the x^2 terms and the x terms:
81 y 2 − 4 = 7 x 2 − 11 x + 6 81y^2 - 4 = 7x^2 - 11x + 6 81 y 2 − 4 = 7 x 2 − 11 x + 6
Now, we have a quadratic equation in terms of x. To further solve for x, let's set the equation equal to zero:
7 x 2 − 11 x + 6 = 0 7x^2 - 11x + 6 = 0 7 x 2 − 11 x + 6 = 0
This is a quadratic equation in the form of a x 2 + b x + c = 0 ax^2 + bx + c = 0 a x 2 + b x + c = 0 . To solve for x, we can use factoring or the quadratic formula. Let's use factoring:
Step 5: Factor the quadratic equation:
7 x 2 − 11 x + 6 = ( x − 2 ) ( 7 x − 3 ) = 0 7x^2 - 11x + 6 = (x - 2)(7x - 3) = 0 7 x 2 − 11 x + 6 = ( x − 2 ) ( 7 x − 3 ) = 0
Now, we can set each factor equal to zero and solve for x:
x − 2 = 0 or 7 x − 3 = 0 x - 2 = 0 \quad \text{or} \quad 7x - 3 = 0 x − 2 = 0 or 7 x − 3 = 0
Step 6: Solve for x:
x = 2 or x = 3 7 x = 2 \quad \text{or} \quad x = \frac{3}{7} x = 2 or x = 7 3
Now that we have the values of x, we can find the corresponding values of y by substituting these values back into the original equation:
For x = 2 x = 2 x = 2 :
81 y 2 − 4 = ( 2 − 2 ) ( 2 + 3 ) + 6 ( 2 − 1 ) 2 = 0 + 6 × 1 = 6 81y^2 - 4 = (2 - 2)(2 + 3) + 6(2 - 1)^2 = 0 + 6 \times 1 = 6 81 y 2 − 4 = ( 2 − 2 ) ( 2 + 3 ) + 6 ( 2 − 1 ) 2 = 0 + 6 × 1 = 6
81 y 2 = 6 + 4 = 10 81y^2 = 6 + 4 = 10 81 y 2 = 6 + 4 = 10
y 2 = 10 81 y^2 = \frac{10}{81} y 2 = 81 10
y = ± 10 9 y = \pm \frac{\sqrt{10}}{9} y = ± 9 10
For x = 3 7 x = \frac{3}{7} x = 7 3 :
81 y 2 − 4 = ( 3 7 − 2 ) ( 3 7 + 3 ) + 6 ( 3 7 − 1 ) 2 = − 44 49 + 36 49 = − 8 49 81y^2 - 4 = \left(\frac{3}{7} - 2\right)\left(\frac{3}{7} + 3\right) + 6\left(\frac{3}{7} - 1\right)^2 = -\frac{44}{49} + \frac{36}{49} = -\frac{8}{49} 81 y 2 − 4 = ( 7 3 − 2 ) ( 7 3 + 3 ) + 6 ( 7 3 − 1 ) 2 = − 49 44 + 49 36 = − 49 8
81 y 2 = − 8 49 + 4 = 8 49 81y^2 = -\frac{8}{49} + 4 = \frac{8}{49} 81 y 2 = − 49 8 + 4 = 49 8
y 2 = 8 49 × 81 y^2 = \frac{8}{49 \times 81} y 2 = 49 × 81 8
y = ± 2 2 63 y = \pm \frac{2\sqrt{2}}{63} y = ± 63 2 2
So, the solutions to the equation are:
x = 2 x = 2 x = 2 and y = ± 10 9 y = \pm \frac{\sqrt{10}}{9} y = ±
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