Question

3(-4n - 9) = 21 plc solve ​

Answer 1

`\Huge \boxed{n=-4}`

Step-by-step explanation:

First thing you do is divide by 3 from both sides of equation.

`\displaystyle (3(-4n-9))/(3)=(21)/(3)`

Simplify.

`\displaystyle -4n-9=7`

Then add by 9 from both sides of equation.

`\displaystyle -4n-9+9=7+9`

Simplify.

`\displaystyle 7+9=16`

`\displaystyle -4n=16`

Divide by -4 from both sides of equation.

`\displaystyle (-4n)/(-4)=(16)/(-4)`

Simplify, to find the answer.

`\displaystyle 16/-4=-4`

`\huge\boxed{\textnormal{N=-4}}`, which is our answer.

Answer 2

`\huge{\boxed{n=-4}}`

Step-by-step explanation:

`\begin{array}{cc}\begin{flushright}\text{Divide both sides of the equation by 3.}\end{flushright}&\begin{flushleft}-4n-9=7\end{flushleft}\\\begin{flushright}\text{Add 9 on both sides.}\end{flushright}&\begin{flushleft}-4n=16\end{flushleft}\\\begin{flushright}\text{Divide both sides by -4.}\end{flushrigh}&n=-4\end{array}`