Set of your problem as followed.24.5=−2.5c−4c
Then you simplify both side of your equation
24.5=−6.5c
Flip your equation now
−6.5c=24.5
Divide both sides of the equation by "-6.5"
−6.5c−6.5=24.5−6.5 (imagine a line going through the equal sign)
and your answer comes toc=−3.769231
To simplify even further, you'll round.
Since 9 is bigger than 5 then you'll round up to the nearest number. Which is 7. So your answer comes to
6=-3.77
Hope this helps. :)