11(x^2-5)=11(3x+5) what is the answer?

2008-11-11 7:17 am
Can u show the work?

回答 (9)

2008-11-11 7:20 am
✔ 最佳答案
11x^2 - 55 = 33x +55
11x^2 - 33x -110 = 0
11(x^2-3x-10) = 0
11 (x-5)(x+2) = 0
There's 2 solutions: x = 5, x = -2

Gimme my 10pts please!! Thank you!
2008-11-11 6:54 pm
11(x^2 - 5) = 11(3x + 5)
x^2 - 5 = 3x + 5
x^2 - 3x - 5 - 5 = 0
x^2 - 3x - 10 = 0
x^2 + 2x - 5x - 10 = 0
(x^2 + 2x) - (5x + 10) = 0
x(x + 2) - 5(x + 2) = 0
(x + 2)(x - 5) = 0

x + 2 = 0
x = -2

x - 5 = 0
x = 5

∴ x = -2 , 5
2008-11-11 3:42 pm
Cancel 11s

x^2 - 5 = 3x + 5

Move all to one side

x^2 - 3x - 10 = 0

Factorise

(x + 2)(x - 5)

Make each bracket = 0 and solve for x

x + 2 = 0, x - 5 = 0

Therefore, x = -2 or 5
2008-11-11 3:27 pm
11(x²-5) = 11(3x+5)
(x²-5) = 11/11(3x+5)
x²-5 = 3x+5
x²-3x-10 = 0
(x-5)(x+2) = 0
x=5 or x= -2
2008-11-11 3:26 pm
11(x²-5)=11(3x+5)
Divide by 11 both sides
x² - 5 = 3x + 5
x² - 3x - 10 = 0
Factor
(x + 2)(x - 5) = 0
Equate each factor to 0
(x + 2) = 0
x = -2
(x - 5) = 0
x = 5
2008-11-13 11:59 pm
11 x ² - 55 = 33 x + 55
11 x ² - 33 x - 110 = 0
x² - 3x - 10 = 0
( x - 5 ) ( x + 2 ) = 0
x = 5 , x = - 2
2008-11-11 5:08 pm
divide both sides by 11
x^2-5=3x+5
subtract 3x+5 from both sides.

x^2-3x-10=0
factor (x-5)(x+2)=0

the left side will be 0 if at least one of the factors is.
When x-5=0
or x+2=0

solving give x=5
x=-2
2008-11-11 4:46 pm
11(x^2 - 5) = 11(3x +5)

11x^2 -55 = 33x + 55

Subtract -33x from both sides of the equation.

11x^2 - 55 - 33x = 33x + 55 -33x

11x^2 - 55 - 33x = 55

Add +55 to both sides of the equation.

11x^2 - 55 - 33x + 55 = 55 + 55

11x^2 - 33x = 110

Subtract -110 from both sides of the equation.

11x^2 - 33x - 110 = 110 - 110

11x^2 - 33x - 110 = 0

Factor out the Greatest Common Factor (GCF) = 11

11(x^2 - 3X - 10) = 0

Divide both sides of the equation by 11. Dividing 0 by any non-zero number is 0.

x^2 - 3x - 10 = 0

Factor a trinomial.

(x + 2) (x - 5) = 0

Multiply using the FOIL Method to confirm.

x x x = x^2

x x -5 = -5x

2 x x = 2x

2 x -5 = -10

x^2 - 5x + 2x - 10 = 0

= x^2 - 3x - 10 = 0

Subproblem 1

x + 2 = 0

Add -2 to each side of the equation.

x + 2 - 2 = 0 - 2

x = -2

Subproblem 2

x - 5 = 0

Add +5 to each side of the equation.

x - 5 + 5 = 0 + 5

x = 5

Solution:

x = -2, 5
2008-11-11 3:25 pm
11(x^2 - 5) distribute the 11
11x^2 -55 (now do the other side of the equation)
33x + 55 = 11x^2 -55 Simplify and Add Like Terms
33x = 11x^2 Add 55 to each side
1 = 1/3x divide by 33x
3 = x multiply by 3

OOPS, my bad! Sorry, I messed up on the second step! Use the first persons answer...


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