We have the expression:
[tex]-8c+13=47[/tex]Step 1. Substract 13 to both sides:
[tex]-8c+13-13=47-13[/tex]+13-13 on the left side cancel each other, and we are left with the following equation:
[tex]-8c=47-13[/tex]On the right side, we have that 47-13=34, thus:
[tex]-8c=34[/tex]Step 3. Divide both sides by -8:
[tex]\frac{-8c}{-8}=\frac{34}{-8}[/tex]On the left side, the -8 on the numerator and the -8 on the denominator cancel each other:
[tex]c=\frac{34}{-8}[/tex]And the result of the division on the right is -4.25, thus:
[tex]c=-4.25[/tex]