Why is this the answer? (algebra)?

Question

x^2 = 9x

answer: x=9,0

(^ means exponent)

please explain why this is the answer.

thanks!

Answer 1

Starting with:

x^2 = 9x.

Divide both sides by X:

(X^2)/x = 9x/x

X^2 is the same as X times X; If you divide it by X you get X and

When you divide 9X by X you get 9:

X = 9

Answer 2

x^2 = 9x

x^2/x = 9

x = 9

That's one answer but because ALL of the values are dependent on the value of x as a coefficient, the answer can also be 0.  

Answer 3

do your own homework.

Answer 4

Well just put the numbers in the place of x:

for x=9 :   9 to the 2nd power = 9x9 = 81

for x=0 :   0 to the 2nd power = 0x0 = 0

Whether you input a 9 or a 0, the equation is true.

Answer 5

x^2 = 9x (subtract 9x from both sides)

x^2 - 9x = 0 (factor out an x)

x(x - 9) = 0 (according to the zero-product property, x = 0 or x - 9 = 0)

x = 0 or x - 9 = 0

x = 0 or x = 9 <===ANSWER

Answer 6

Remember that whatever you do to one side of an equation, you must do to the other side of the equation to maintain equality.  So....

x^2 = 9x

Subtract 9x from each side

x^2 - 9x = 9x - 9x

x^2 - 9x = 0

Now, factor the left side.  Note that there is an "x" in each value

x*x - 9*x = 0

x(x - 9) = 0

Now, use the zero property which states that if two numbers multiply to 0, one of them must be 0.

So...

x = 0 or (x - 9) = 0

finally

x = 0 or x = 9

Answer 7

x² = 9x

x²/x = 9x/x

x = 9

Answer: x = 9

Proof (substitute x with 9):

9² = 9(9)

81 = 81

Answer 8

x^2 = 9x

x^2 - 9x = 0

(x)(x-9) = 0

For the left side to equal the right, (x) = 0  OR (x-9) = 0

So, x can equal 0 or 9 to make the equation work.

x= 0 or 9

Answer 9

x^2 = 9x..........subtract 9x from both sides to set it equal to zero

x^2 - 9x = 0.......factor

x ( x - 9) = 0  ....use zero product property

x = 0   OR  x = 9

Good luck to you !!

Answer 10

Subtract 9x from both sides:

x^2 - 9x + 0 = 0

Now use the Quadratic Formula:

x=[9±√81]/2

[9±9]/2

So that's 18/2=9 or 0/2=0.

Or, you can divide by x on both sides to get 9, then realize that if x=0, both sides are 0 as well. But that's risky with more complex problems, where 0 may be the only answer, so dividing by x is undefined.

-IMP ;) :)