# help

• April 16th 2006, 10:40 PM
jim1174
help
can some one show me how to do this problem

negative four times the sum of n and seven is equal to negative five times n minus nine
• April 17th 2006, 12:09 AM
CaptainBlack
Quote:

Originally Posted by jim1174
can some one show me how to do this problem

negative four times the sum of n and seven is equal to negative five times n minus nine

Translated into an equation this is:

$
(-4)(n+7)=(-5)(n-9)
$

Multiply both sides of the equation by $-1/4$, and as
a "-" times a "-" is a "+" this gives:

$
n+7=(5/4)(n-9)
$

Now expand the brackets on the Right Hand Side of the equation:

$
n+7=\frac{5}{4}n-\frac{45}{4}
$

Add 45/4 to both sides of the equation:

$
n+\frac{73}{4}=\frac{5}{4}n
$
.

Subtract $n$ from both sides:

$
\frac{73}{4}=\frac{1}{4}n
$
.

Finlay multiply both sides by 4:

$
73=n
$
,

so $n=73$

RonL