### Home > GC > Chapter 1 > Lesson 1.1.2 > Problem1-17

1-17.

1. $−11x=77$

• Divide both sides by $−11$.

• Simplify.

• $x=−7$

1. $5c+1=7c−8$

• Move all variables to one side of the equation.

$5c+1=7c−8$
$\ −5c\ \ \ \ \ \ −5c$
$1=2c−8$

Add $8$ to both sides to isolate the variable.
$1=2c−8$
$+8\ \ \ \ \ +8$
$9=2c$

Solve for $c$ by dividing both sides by $2$.
$\frac{9}{2}= \frac{2c}{2}$

$c=4.5$
1. $\frac{x}{8}=2$
• Mutliply both sides of the equation by $8$.
$x=16$
1. $−12=3k+9$
• Subtract $9$ from both sides of the equation.