#### Answer

The solution is 3

#### Work Step by Step

-7c+1=-20 Subtract 1 from both sides
-7c+1 -1=-20 -1 Simplify
-7c =-21 Divide by- 7 on both sides
$\frac{-7c}{-7}$ =$\frac{-21}{-7}$
c=3
The solution is 3
Check
-7c+1=-20
-7$\times$3+1=-20
-21 +1=-20
-20=-20