Im doing a powerpoint on a math problem?

Question

9(x-9)=-11, then x=?

Answer 1

We are dealing with an equation in one variable, so we know that the operations on the left side, once performed, will yield -11.

 

9 * (x - 9) = -11

 

Equal things divided by equal things yield equal things, so,

 

(9 * (x - 9)) / 9 = -11 / 9

or

 

(x - 9) = -11 / 9 

 

Divide both sides by 1 to mathematically remove the grouping symbols, so

 

x - 9 = -11 / 9

 

Equal things added to equal things yield equal things, so

 

x - 9 + 9 = (-11 / 9) + 9

or

 

x = (-11 / 9) + 9

 

In order to add the whole number to the fraction, we must convert the whole number to an equivalent fraction and then convert to lowest common denominator.

 

x = (-11 / 9) + 81 / 9

 

x = 70 / 9

 

And you would simplify from there. 

Hope this helps! :D