Hello! I'm doing some review for a math placement test tomorrow. I can't remember how to solve this sort of equation:
Solve 4x^2 = 20x -24
I just know that it will have two answers. Please try to show the steps you used and I can probably figure out what you did.
Thanks for the help!
Solve 4x^2 = 20x -24
I just know that it will have two answers. Please try to show the steps you used and I can probably figure out what you did.
Thanks for the help!
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Bringing all the terms in lhs we get
4x^2 - 20x + 24 = 0
Divide the equation by 4 we get
x^2 - 5x +6 = 0
=> x^2 - 2x - 3x +6 = 0
=> x(x - 2) - 3(x - 2) = 0
=> (x - 2)(x - 3) = 0
=> x = 2, 3
4x^2 - 20x + 24 = 0
Divide the equation by 4 we get
x^2 - 5x +6 = 0
=> x^2 - 2x - 3x +6 = 0
=> x(x - 2) - 3(x - 2) = 0
=> (x - 2)(x - 3) = 0
=> x = 2, 3
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this is a quadratic equation of the form
ax^2 +bx +c=0
bringing all the terms in lhs we get
4x^2 - 20x + 24 = 0
divide the equation by 4 we get
x^2 - 5x +6 = 0
i.e. x^2 - 2x - 3x +6 = 0
i.e. x(x - 2) - 3(x - 2) = 0
i.e. (x - 2)(x - 3) = 0
therefore x-2=0 and x-3=0
hence x=2 and x=3
ax^2 +bx +c=0
bringing all the terms in lhs we get
4x^2 - 20x + 24 = 0
divide the equation by 4 we get
x^2 - 5x +6 = 0
i.e. x^2 - 2x - 3x +6 = 0
i.e. x(x - 2) - 3(x - 2) = 0
i.e. (x - 2)(x - 3) = 0
therefore x-2=0 and x-3=0
hence x=2 and x=3
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4x² = 20x - 24
x² - 5/2x = - 6 + (- 5/2)²
x² - 5/2x = (- 24 + 25)/4
(x - 5/2)² = 1/4
x - 5/2 = ± 1/2
x = 5/2 - 1/2, x = 4/2, x = 2
x = 5/2 + 1/2, x = 6/2, x = 3
Answer: x = 2, 3
Proof of equality in two equations:
4(2)² = 20(2) - 24
4(4) = 40 - 24
16 = 16
4(3)² = 20(3) - 24
4(9) = 60 - 24
36 = 36
x² - 5/2x = - 6 + (- 5/2)²
x² - 5/2x = (- 24 + 25)/4
(x - 5/2)² = 1/4
x - 5/2 = ± 1/2
x = 5/2 - 1/2, x = 4/2, x = 2
x = 5/2 + 1/2, x = 6/2, x = 3
Answer: x = 2, 3
Proof of equality in two equations:
4(2)² = 20(2) - 24
4(4) = 40 - 24
16 = 16
4(3)² = 20(3) - 24
4(9) = 60 - 24
36 = 36
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4x^2=20x-24
4x^2-20x+24=0
Then use the Quadratic equation:
x1,2 = -b ± sqrt( b^2-4ac )
------------------
2a
(a= 4; b= 20; and c=24
x=2
x=3
4x^2-20x+24=0
Then use the Quadratic equation:
x1,2 = -b ± sqrt( b^2-4ac )
------------------
2a
(a= 4; b= 20; and c=24
x=2
x=3
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put in form so you can factor...
4x^2-20x+24=0 find factor of equations
(2x-4)(2x-6) take 2 out of whole eq..
2(x-2)(x-3) x=2or x=3
4x^2-20x+24=0 find factor of equations
(2x-4)(2x-6) take 2 out of whole eq..
2(x-2)(x-3) x=2or x=3
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4x^2 - 20x + 24 = 0
x^2 - 5x + 6 = 0
x^2 - 3x - 2x + 6 = 0
x (x-3) -2 (x-3)
x=2 , x =3
x^2 - 5x + 6 = 0
x^2 - 3x - 2x + 6 = 0
x (x-3) -2 (x-3)
x=2 , x =3
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4x^2 - 20x + 24
x^2 - 5x + 6
(x - 6)(x + 1)
x^2 - 5x + 6
(x - 6)(x + 1)