Question

Which of the following is a solution to the equation ¾x-12=-18?

Answer 1

miren pongan enpeño en matematica

Answer 2

$\frak{Hi!}$

$\orange\hspace{300pt}\above2$

                     We have the equation $\large\boldsymbol{\sf{\displaystyle\frac{3}{4}x-12=-18}}$.

                     First we should add 12 to both sides of the equation.

                     $\large\boldsymbol{\sf{\displaystyle\frac{3}{4}x=-18+12}}$. Simplify

                    $\large\boldsymbol{\sf{\displaystyle\frac{3}{4}x=-6}}$.

                   This done, let's multiply the equation by 4. You'll see why

                   $\large\boldsymbol{\sf{\displaystyle\frac{3}{\not4}x\times\not4=-6\times4}}$

                   Did you see how on the left, the 4's cancelled? That's

                   because dividing by 4 and then multiplying the same

                   number, or the result, by 4, are operations that undo each

                   other.

                   This being said, let's finish solving this equation in terms of x

                   $\large\boldsymbol{\sf{3x=-24}}$. See how this works?

                  Now, remember that we ought to use inverse operations

                  to solve for x. These are operations that undo each other.

                  So if x is multiplied by 3, we should... divide by 3!

                  Also, please keep in mind that we can only divide the left side

                  by 3 if we divide the right side by 3.

                 $\large\boldsymbol{\sf{\displaystyle\frac{3x}{3}=\displaystyle\frac{-24}{3}}}$. Once again the 3s on the left cancel, leaving

               x. Wait! Isn't that what we wanted? Yepp, sure!

               The right side is now -8. Thus,

               $\large\boldsymbol{\sf{x=-8}}$

                 $\orange\hspace{300pt}\above3$